I A/B a pair of them against a pair ov EV-TX1181's pushed with a Q1212 amp. I used the EV-TX1122 tops on both sides. I could not tell much difference until I pushed the subs hard. The QSC went flat, I guess some call it roll off, while the TX hammered all the way till I was lighting the limit light about every couple seconds (flashed the light would be the right term), no limiting ever took place. The Q1212 amp was feed by the same mixer but it had a DCONE processor in line, with the subs getting 40-100HZ.
I feel it was more than a fair test as the salesman was doing everything he could to get me to buy the QSC stuff, I am guessing much better commission or product bucks for that line. Myself, and I am no engineer (on audio that is), I think the amps and processing in the QSC was not up to the level of the amp and processor from EV. I also think that line of sub is really suffering from the cabinet size, it might be very portable, but not enough air space.
This is no ding on QSC, I thought thier tops were tremendous, and thier subs would be great for small rooms or flat music, I do a lot of teen stuff and many old school disco events and I feel thier subs don't put out the grunt at higher volumes like many other do.
Ray J.