This booster basically does what they say it will, but with a huge caveat. I'm experienced with Wilson since I had the Wilson sleek for a couple of years until it failed just after the warranty expired. So I decided to go all in and get the best booster they offer for use in my rv which we travel fulltime in. I also ordered the Wilson ac/dc adapter #859900, since the unit only comes with the 12v DC cigarette lighter type plug cord. I first set it up with the ac/dc adapter so it was running on a 120v AC power source and it worked wonderfully( 4-5 bars on the cell phone and internet pages loaded on about 2 seconds with it boosting our Verizon mifi card. But I really wanted to run the booster on 12v DC power in the rv because it's much more efficient than having our inverter convert 12 volt battery power to 120 volts and using the 120v AC plug. There is a significant waste, or loss of electricity in that conversion process of 12v DC to 120v AC. So running the booster on a 12v source saves precious battery life when camping off the grid and living on our batteries. What Wilson neglected to tell me or anyone else is that the two different power cords are putting completely different levels of power into the booster. The 12v DC plug that comes with the unit has a small conversion box half way down the length of the cord that converts the 12v DC power source down to 6v DC going into the booster. On the other hand, the 120v AC power cord has a box that converts the 120v AC power source down to 12v DC going into the booster. That's twice as much power as the 12v DC cord. As mentioned earlier, when hooked up to the 120v AC cord that reduces down to 12v, my internet pages load in 2 seconds. But when hooked up to the 12v DC cord that's reducing down to 6v, my internet pages take at least 20-30 seconds or longer to load.
The other, related, but less significant issue is the heat coming off the booster. When running on the 12v DC cord the heat coming off the booster measures 98 deg.. When running on 120v AC, the heat measures 125 deg. and customer service admitted it can run as high as 150 deg., though they claim it will not damage the booster. 150 deg. is too hot to touch so you would want to be careful where you mount it so it doesn't touch flammable materials.
I will give Wilson's customer service dept. credit for their quality of service. They answer fairly quickly(1-3 min), they speak clear English, they seem to be fairly knowledgeable about the products and they do seem eager to help. They offered to send me a 12v DC cord that does not reduce the voltage down to 6v. which should solve my slow internet problem, but I will still have a very hot unit with 12v going into it. Reducing the input power form 12v to 6v drastically reduces the performance of the booster. These differences are significant and should be made clear to prospective customers. In my four conversations with customer service prior to purchasing the unit, the difference in performance between 12v and 120v power sources was not mentioned.
The booster appears to made of die cast metal and is very sturdy. When I first set it up, I was not getting all four green lights and learned from a follow-up call to customer service that you need to keep the inside antenna away from windows which causes the inside and outside antennas to compete and cause feedback that reduces effectiveness.
I'm now satisfied with the booster but there were some problems that had to be overcome.

UPDATE: 11/07/2017
I've had 2 years experience with this booster now & decided to upgrade from 3 to 4 stars. I've mostly used the 6 volt power adapter but occasionally use the 12 volt adapter if I'm in a particularly remote area & the booster doesn't seem to be up to the task. Sometimes that seems to help, though I can't definitively say it's the different adapter that does it. Overall I'm pretty happy with the booster. We do a lot of boondocking around the country or have worked in remote areas of south Texas as gate guards. We use both Verizon & ATT cell/data service & we've only had once or twice that we got no signal. It typically boosts the signal 2-3 bars & from 1x to 3G or 4G. I've been in many remote areas where others nearby said they couldn't get any Verizon or ATT signal, while we were getting at least 3G or better. On rare occasions we've been way off the grid and appeared to get no signal for our cell phones or laptops. But when I placed the phone or either hotspot directly on top of the booster I was able to get a usable signal.
The one annoying thing is frequently 1 or 2 of the lower of the 4 green lights starts flashing red, meaning it's not working optimally. So I shut it down for 10 seconds & turn it back on. This usually solves the problem, at least for awhile. Otherwise adjust the direction you have the final booster aimed. We have it between my wife's & my chair & the flat panel aimed towards the middle of the rv , about a foot off the floor & away from the 4GX that's mounted up inside an overhead cabinet at the rear of the room. We also keep it aimed away from windows. The smooth side of the booster is what you're aiming, not the velcro side. Aiming the velcro side will have the opposite effect of what you want. And the booster must be within 3-6 feet of the phone or hotspot to get the best performance.
So with a little bit of work & experimenting, we've succeeded in getting it to do exactly what it's supposed to do. And it seems to work equally well for our Verizon Myfy & our ATT Mobley hotspots.

Okay, let's get the BS out of the way, I own a Class A motorhome which is a fiberglass body. The magnetic mount external antenna will never work on fiberglass, it requires a ground plane (hence the magnet) from a metal body. Had this for 1 year and never saw it do anything for my signal. I was getting ready to throw it out but then decided to call Wilson tech support. They suggested I use silicon sealant to glue down a piece of flat metal to my RV roof to use the factory antenna. I did not buy a Newmar diesel to glue crap to my roof!

So then they tell me that a new cellular exterior antenna has just been released for semi's and RVs. It is the 4G-OTR Antenna (Truck Edition). Priced is steep at $99.00, but I need maximum coverage when parked. I ordered one from Wilson and received it within 2 days. This thing is LONG, 19" without the mount bracket, so I cannot mount it on the roof of my RV, it would clip the first bridge I went under. And, it must be mounted vertically to work correctly. I personally think it is too ugly to hang off the side of my RV to eliminate the height issue.

I need this when I am parked, not driving. So I find this pesky tv antenna on my roof that has never been used........

I used a piece of 1.25" aluminum L and built a small mount that mounted to my crank-up antenna frame. When the antenna is raised, the cellular antenna is perfectly parallel. When the antenna is lowered for travel, the cellular antenna sits parallel to my roof. This works like a charm now, my signal went from -121 DB to -79 DB in the coach!

**** UPDATE 9/13/17 ****
I'm bumping up my review from 4 to 5 stars. The device is amazing and easily a 4 star rating. Now because of the ease of reporting and timeliness of their tech support responses, and no hassle exchange for a refurbished unit, they are a *solid* 5 star rating.

I reported my broken antenna connector issue to WeBoost, complete with exactly what I did to break it and included pictures of the broken part and board. (see below)

Their response? Once I gave them the SN of my device so they could confirm it was under warrantee, they issued an RMA, and replaced my device for the cost of sending the old unit back.

WeBoost is one of the most responsive companies to information requests and warrantee questions I've done business with in years.

Also, I got a work tablet that uses Verizon. This device boosts both the Verizon and AT&T simultaneously. Awesome for my work environment!

**** UPDATE 9/3/17 ****
I'm totally in love with this device. Made my office almost as big as North America.

Note to all boondockers!!
I used a small wrench to just touch a little extra on the antenna connectors to keep them from backing out on washboard roads.
Finally got to a point where I wanted to do a permanent install. Got everything mounted and cables run the way they needed to be. Then used the wrench again (light touch) for the final install. (FAR less than used by the cable guy on their el-cheapo cable modem for internet)

MASSIVE mistake! Turns out, even though this units shell is built like a tank, and cable strain relief is like like nothing I've ever seen - the antenna connectors are only soldered to the board - NOT bolted to the case.

My light touch for the third time ripped the antenna connector clean off, and tore out all the traces on the board. I'm not hopeful I can repair it.

Long and short? AWESOME device!! Just NEVER tighten past finger tight, and get in the habit of checking the connections every few hundred miles if you spend a lot of time on washboard roads.

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Bought this device a month ago. I'm on AT&T with an LTE phone.

First test-bed spots I tried it in, I only had mild success but was in steep and deep terrain in Olympics.

I've since used in a number of places in the Northern Rockies (MT, ID) and Cascades (OR, WA). I went from "No Service" to two bars LTE (-105db to -110db) with phone 3' to 5' from internal antenna. I could reliably text but not send pictures or use much internet bandwidth when using phone as hotspot.

If I put the phone ON the antenna, I measured -85 LTE. Big data took time, but eventually went. I was even able to VPN to remote networks.

PROS:
Easy to install.
Easy to use (turn it on/off)
Brought coverage to huge areas previously showing "No Service"

Watch-outs:
Be sure to give the booster device breathing room. It can run warm if you don't.

You're locked into the default antenna, or another $100 for the trucker antenna, which doesn't get you that much gain (on paper at least).

The directional antennae aren't certified with the FCC, so their use could be a violation of law and and telco contract.

Be sure to enable LTE for both voice and data. Data only = no cell phone service. (Voice & data got me both just fine.)

Summary:
Amazing product! Hoping to test Verizon, T-mobile, and Sprint devices in the next few months.

If I could do it over? I think I'd get the Drive 4G-S Sleek 4G and saved a few hundred dollars.