"I don't pass on an opportunity to badmouth them"
Yeah, we noticed.
I've been using the the DC2000CF (canister filter) for about two years, and I'm happy with the performance. The limiting factors for DC performance are impeller size, duct size, and filter type and area. As long as the motor is powerful enough to turn the impeller at rated speed, it doesn't matter whether it's 2 HP or 20 HP. The DC2000 has a
12" impeller, and it will perform the same as other machines of comparable design.
If I were shopping today, I'd take a good look at the Delta 70-560. The impeller is a bit smaller (11.5"), but it has a larger outlet, which should equalize things. Comes with a good filter bag, and the price is under $300 with free shipping from several vendors.