This compact tank water heater is pretty much perfect for installing under a counter. Running it it in parallel with what you already have is a good way to get supplemental hot water until your primary can deliver it to you. I think most people will use it for that purpose, and it works well for that. My tank is on the opposite side of the house, and on a cold day, it's a bit of a wait to get comfortably hot water. This is now solving that problem, and it was relatively easy to install. I think a lot of people who are handy could easily install this themselves, but you could also ask someone you know for assistance, or simply pay someone to do it for you. I could also see some other great uses for this. If you have a separate shop, pool house, or other spot without hot water, this could be just the ticket. This might also be a good solution for an RV or camping unit. I went with the 8 gallon unit, which is a good amount of water. That is enough to buy some time for your primary to get hot water down the line. If you are using it as a standalone, 8 gallons is enough for casual use or even a quick shower or two, especially if you are using a low flow or oxygenating shower head. Definitely happy with this and the price is more than reasonable.