bigdog360,
Listen to PoolDoc. He speaks truth!

For example, the builder saying that the whisperflo will only last 3 to 6 years is just trying to sell you up to a more expensive product that he probably has a better profit margin on. Truth is the the two pumps use IDENTICAL pump parts, only difference is the motor and control electronics on the intelleflo vs a one or two speed "standard' motor on the whisperflo, and they are both made by Pentair. Considering that the whisperflo is the simpler design I would put my money on it being the one to perform longer without problems! (And I have a whisperflo on my own pool!)