We bought this to replace an older shower head only unit.  The plumber put it in for us and we couldn't get enough hot water, only to be told the cartridge was bad.  So we called Delta and got a new cartridge.  Finally it worked right and was good a few months.  Then suddenly we had no water pressure with hot water.  After disassembling everything, we discovered the cartridge had gone bad again.  Bought another cartridge.  This time it seems to be ok, but now the top of the shower head will not stay in place so the entire head and hand shower just drops down and you basically have to stand right against the wall.  SO frustrating!  I would have been better off spending my money somewhere else.