I have a WhisperFlo Pump 1 hp single speed. The pump was rated well a year or two ago when I bought it. It has served me well without any issues.

If I had it to do over again I would buy the 1hp two speed version because I have a polaris 380 (pressure cleaner).

FYI the 1 hp motor is actually an under-rated 1.5 hp motor. I would assume the impeller is the only difference between 1 and 1.5 pump???

1hp motor nameplate data:
1 hp and 1.65 SF (service factor)

The pump primes well and has been run for 8 hours a day for a week "DRY". I was out of town and the wife was operating the pool. She set the valve to waste and forgot about it... The pump wet/dry seal is doing fine.

So overall I give it a thumbs up.