I had one I got as a B Stock for $375, but sent it back. It just didn't have enough balls until you trottled it about 80% for gigging volume. I Bought the SWR 550X, and had the same issue. I Use the PLX 1602 but also a Peavey T max for back up and primary when the QSC is in the PA rack.
That being said, I would have given it another try for $50 and probably kept it as I am starting to use lower volumes, and push less lows than I used to.
I think it was a great deal for those who got them, and am SURE that MF will make it up hand over fist, even though it is still a mistake on their part.
I did find that if I nudged the front end with a BBE sonic stomp or similar, it really responded well, and played through one at a venue that had the Sansamp bass driver in front, and it was stellar through a svt410Hlf.