Just from reading the posts on pool forums, I get the impression that pool service techs are not all that fond of Hayward because of reliability and design issues. However, many pool owners seem to be happy with their Hayward equipment so it is hard to tell if there is really a difference between the manufactures or not.
Also, I tried to get some insight through this survey but came to no real conclusion.
As for energy efficiency, the Hayward pump designs seem to be a little bit better then Pentair but not enough to sway a decision.
Thanks, Qwaxalot et al: I have ordered another Whisperflo since I see no advantage to change to another brand. I got a good deal from Poolplaza, Carl W. is a wealth of information and very helpful. I highly recommend them.
I must take back my recommendation of Carl at Poolplaza. The pump arrived and the local pool store tech. hooked it up electrically to make sure it ran before he pumbed it. It wouldn't start so he manually turned the motor shaft and it howled like mad.
Called Poolplaza and they said because he ran it dry even for a few seconds he probably burned it out or fried the impeller to the diffuser, which I believe to be untrue. They also informed me that it's a warrenty issue now and won't take it back even though it appears it was D.O.A.
My local pool store is installing another pump today for me and I have contacted my credit card company to dispute the charge since Poolplaza has left me with no other option.
If you live in the Dallas, TX area, or anywhere else for that matter, don't buy from them!!