Just installed so this is based on first impressions. Will update with longer term review. Pull up a chair- this is going to be one of my longest reviews. First, I decided to get this system because it claims to have filters that only need to be changed once per year. Also it has almost twice the daily volume of the 50gpd system. Using a TDS meter, my tap water is around 360 to 340TDS. Ouch - that's very high. Min standards for city water is 400ppm for TDS so this is right below the limit. To compare, distilled water purchased locally has a TDS of about 120 ppm. Some bottled water I had handy was about 30 ish. Installation - Effort: I would rate this as easy for people who've installed things like a sink disposal. My only tools I needed were two adjustable wrenches. Make sure you have a stubby handle adjustable wrench with wide jaws. If one has never installed anything under one's sink then it might be seen as medium easy. What will make this more difficult is deciding and drilling the hole for the faucet. I have a corian/synth marble top so I'm nervous about drilling. Have not done it yet. Many people will have an existing accessory hole so that will make for a much easier install. Time: I took my time and double/triple checked for leaks. Very important. I found a few and had to make some adjustments. It took about an hour. But keep in mind I have yet to drill and install the faucet or waste line (more on that later). I did connect everything up and ran the waste line into a 7.1 liter bowl. The three large main filters need to be unwrapped and installed. All the other filters are pre-installed. What caused me to pause a bit was that the three main filters (sediment pre filter and the two carbon block filters) when placed in the screw on housings, prior to screwing them on; the filters rattle around. There's a good space around each filter. The filters are about an inch smaller in diameter than the inside of the housings. Also I was not quite sure how this would align to the inside of the top portion. I should have taken pics of this. Judging from how it operates after putting it all together I am thinking it must self align. Although there might be potential for mis-aligned filters. I hand tightened the 3 main filters and then snugged them with the supplied wrench. I opted to not use the wall mountings as I would like to keep the filter unit in a small basin as protection against any potential leaks and for monitoring such. That being said - I observed no leaking from anywhere so far. It's only been about 3 hours since I installed it. After assembling the system and connecting it to the cold water supply. One turns on the needle valve to supply and fill the filter and tank. I suppose one could pre-charge the system with filtered water but I let it fill as normal. There was quite a bit of air in the system and I bled that out through the faucet which I had connected but have not drilled and placed into the counter. The first liter of water was blackish due to the carbon dust from the filter. WASTE Water Ratio - OK this was one of my primary concerns. I read here and there people saying this system wastes water. Well, yes - but not on a constant basis. Here's what I found out. For me- as the system and tank filled, the Waste water ran out pretty quickly from the black tube. I timed and measured this. The manual said expect to take 2 to 3 hours during which time the waste water outlet tube will run constantly until the RO filter stops the flow when the 4 gallon pressurized tank is full. I started filling at 11:32 and the waste water tube was filling up 7.1 liter stainless steel bowls at a rate of about 9 to 10 minutes per bowl. At 12:36 the waste water stopped flowing into the bowl. According to the manual - if one has higher water pressure it takes a shorter time to fill/charge the system+tank. So, my water pressure must be a bit higher than 60psi. They also note that if one has lower than 40psi, the system could run all the time meaning waste water would continually drain out and that would be a huge waste of water. WATER PRESSURE NOTE- One should probably test their water pressure before buying this or any other RO filter. Also, if / when water pressure in the house supply drops that will cause the RO filter to open up and your water bill will go up due to water being constantly wasted through this system UNLESS you shut it off except when you are getting filtered water. ALL RO Filters have a ratio of filtered water to "wasted" water. This is because the filter lets by purified water and blocks the contaminants which are carried by the "waste" water. HOW MUCH WATER IS WASTED? So - manual says to drain the first tank. Don't drink the first tank of water. Says that will take about 5 minutes. I drained the system by using the faucet in fully open position. It took about 9 minutes and filled about 2 bowls of 7.1 liters until the water from the faucet slowed to a trickle. So about 14 liters of filtered water. During this time I ran the waste/drain black line to another 7.1 liter bowl. The waste bowl filled up about 4 liters. I shut off the faucet and the system started to re-charge itself. During this time, the waste water drain line continued to flow and I kept close track of this. I ran my stop watch app. Each time the 7.1 liter bowl filled, I registered a lap. First lap / 7.1 liter bowl took about 9min33sec. The second lap / 7.1 liter bowl took about 11:30. Third took 12:07 etc. So the waste water flow was slowing as the tank filled. The waste water stopped flowing at 59minutes and some seconds. About 2:06 into "lap 6". SO - that means 5 whole bowls + about 1/3. Plus about 4 liters of waste water that was produced during the 9 minutes / 14 liters of filtered water "used". To sum up - for the first 14 liters of Filtered Water, my system "wasted" about 6x7.1 liters of water. So ratio is 14 Liters of Filtered Water to 42.6 Liters of "wasted" water. Remember, the system has stopped draining any water since the 4 gallon tank has charged. This means my system with my water pressure will use 3 gallons of water for every 1 gallon of filtered water. This sounds like a massive amount but consider that this is for drinking and most people consume about 1 gallon / person / day. So for an average family of 3 drinking 3 gallons of filtered water per day will also waste / use an extra 9 gallons per day x 30 days = 270 extra gallons per month. For me I use about 2 gallons per day for drinking and cooking so that's only 6 gallons per day more than normal use = 180 gallons extra use per month. NOT Bad and probably not enough to spike or increase my water bill. We'll see. UPDATE - Purchased a 1/2 inch Bosch BlueTurbo Granite Carbide bit to cut through my cultured marble top. WOW. This is tough stuff. Took about an hour to drill through about 2 inches of the counter top. TIP - use a smaller carbide bit 1/8 inch to start the hole to prevent any wandering of the larger bit. Then, use a 1/4 inch bit to widen the hole. Then I used the 1/2 inch bit to go about another inch. Then I went back to the 1/8 and bored all the way through. Then the 1/4 inch through and finished off with the 1/2 inch bit. The Bosch 1/2 inch bit cost about $10 so budget that into your installation and was worn out after. Drilling through a stone/marble counter top increases the difficulty of installation. I would not relish the thought of drilling any more holes through that stuff.