The typical residence doesn't have a large enough water supply to make one of those work without a tank (which could be in the wall). Most require 1" or larger water pipe all the way back to the supply at the street (or your pump, whatever). The other big hassle is the wall usually needs to be at least 6" thick to accommodate the carrier and the pipes. If you can provide those, then you can make it work. The advantages are primarily that it's easier to keep the floor clean, and the look (assuming you prefer it).