I've used 4 of them - an 75x2 Alphasonik (old name, can't remember the model number), a USA-2200F, a USA-4080, and a USX-600D.
The Alphasonik was stolen after flawlessly serving 6yrs of amplification duty in about 12 different cars.
I sold the pretty, chromed 2200F. Didn't need it in my system, the new owner loved it.
I'm still running the 4080 in my CSVT. Its only drawback is running into thermal shutdown after an hour or more of high volume on those 100+ degree summer days. I'm thinking of replacing it with a Blau T-class amp, which I could mount in the factory amp location (I love stealth installs).
I'm absolutely impressed with the 600D. Tons and tons of power. The thing never even gets warm to the touch after hours of use. It's running a IDQ10 at 2ohms in my truck. Awesome sub amp for the $70 I paid for it (had 'em on uBid).
I think you'd be happy with either the 2050 or 2080 (might want to check into the 600D if you're just planning on running a sub).
