August 25, 2017 - Update: Still 5 Stars - Very Pleased!At home, I've been using Unifi for nearly a year and I couldn't be happier. The USG works perfectly with the entire system. They're currently up to USG Version 4.3.49.5001150 and Controller Version 5.5.20. Over the past year, one of the most noticeable things is how far along Ubiquiti has brought the Unifi line through their product updates to the controller and devices. They seem to listen to their customers and work to incorporate their requests.I did some Layer 3 VLAN testing and did not experience any drops or packet loss like another reviewer had reported. I'm using the USG and a 24 port non-POE Unifi switch for testing and had 100% success. USG to USG VPN connections work perfectly - without issue - but getting the USG to create a connection to other devices over IPSEC requires a lot of CLI work and JSON files. As stated earlier, UBNT listens to their customers and they've told me they plan to include the ability to create tunnels to any device in a future firmware release. I still think anyone who has multiple public IP addresses and the need to NAT ports to multiple IPs would be better suited with another solution, but if you've got a single public IP or dynamic (cable/dsl), this would work perfectly.My IT firm has deployed these to about six organizations to date and we have had zero issues. It's been invaluable for us to be able to log into a single console and remotely connect to a client's controller and get instant feedback on their network. We've experienced no Unifi related network outages and clients love the range of the wireless and the fact that they never have to call us about network issues.To those who have had issues with equipment, all I can say is: these are pieces of electronics and it happens. We've deployed enough of these to get a sense of reliability and we're pleased. As a Disaster Recovery plan, we've ordered a few spare units that we've stocked in the office. That way, if a client ever does have an issue, we can easily re-deploy a new piece of hardware - a lot more cost effectively than than if we'd gone with Cisco or another, more expensive, vendor.I'm still very pleased with Unifi and the USG.November 7, 2016 - UpdateIt's been about a month since installing my USG and I have been extremely pleased. I have had zero issues with uptime or reliability and I love having the near realtime visibility into my network statistics.I introduced it to my company (I work for a small IT firm) and we've also been testing it there for the past month. We started with a USG, Unifi Switch 24-150w, a cloud key and a UAP-AC-PRO but upgraded the USG to a USG-PRO-4 - everything has works flawlessly. We're in the process of rolling it out to a few smaller customers who don't need everything Cisco has to offer and my co-workers have been blown away with the ease of management/configuration and we all love the iOS app/remove management using Chrome.We have discovered that there is a very specific setup process for these and you can only adopt one USG per Unifi Controller. If you wish to replace/update the USG, you must first forget the one paired with the controller. Just a small caveat I thought I'd share.I'll post updates as I have them and/or maybe as we roll them out to customers.October 11, 2016 - Original ReviewAs far as I can tell, the Ubiquiti Unifi Security Gateway has come a long way. I came across Ubiquiti's Unifi line about five months ago (May, 2016) when I purchased a pair of WAPs for my home. I was so impressed with their Wireless products that I decided to give their USG a shot. If you notice, the reviews for this unit have gradually gotten better and better as Ubiquiti has released newer versions of their controller and firmware.I'm currently using the USG with the Unifi Cloud Key, version 5.2.9 and this whole setup works flawlessly. My LAN IP scheme is different than what comes default on the USG, so my setup required a few additional steps but it wasn't difficult by any means. Essentially, I had to run their controller application locally from my computer while giving my computer a static IP address and connected to the LAN port of the USG. I adopted the USG to the local controller, then adjusted my site network to the correct IP range. Once the USG had the new IP address, I connected it up to my live network where I was able to use my Cloud Key to adopt the USG and that was it.The unit itself feels physically sturdy - the case is metal and feels very well made. It comes with the USG, a power adapter, instruction guide and wall screws in the box. When powered up, prior to being configured, the square on top flashes white which changes to blue once configured. As stated above, initial configuration was pretty simple. Once that's done, new configuration is handled through the controller, but CLI is also avaiable. Configuring port forwarding couldn't be easier as it requires only a few simple clicks to complete. The new version of the Controller adds features for Routing as well as advanced Firewall control, as well as some nifty autobackup features for the Cloud Key.I actually upgraded from a Ubiquiti Edgerouter Lite so I could take full advantage of the Data Packet Inspection and having the real-time view of my network and bandwidth. I really like the main dashboard screen that shows the current bandwidth utilization, your attached Unifi Devices as well as the top devices, clients and top users (if DPI is enabled).I feel slightly ridiculous seeing that I have 33 devices connected to my home network but, since this is what I do for a living, I find it very helpful to have that kind of visibility. My plan is to ultimately replace the core switch in my home lab with a Unifi 24 port PoE to do some additional testing with their VOIP security cameras and NVR and/or their VOIP desk phones.I am very pleased with my purchase and have already recommended the Ubiquiti Unifi solution to several of my coworkers/friends.