Chinese crapola... It would be a total waste of money to purchase their amp. You'd be a lot better off getting the Emotiva UPA-2 for a hundred bucks more.
Funny, I've read way more complaints on Emotiva products than these "crapola" Behringer ones.
Won't argue with you over Chinese business practises, or lack there-of, though.
Charles, how's the QSC working out for you?
Tom, I think FredK would be the guy to talk to about using one of these pro-amps on a sub. I believe they are quite popular in the DIY crowd.