I've had an Aquacal Icebreaker reverse cycle model for several years now. Works great at both heating AND cooling ( but I rarely use the cooling feature since I like my pool WARM! However, the few times I did it really cooled the pool off quickly!) Main advantage for me with the reverse cycle is that it works well on the few nights of the year that temps drop into near freezing and freezing range in N. Fl. since it also heats my spa and those are the best nights for the spa! Standard heat pumps become useless below about 50 degrees ambient temp.