I would love to side by side compare some of these more expensive types. 2 things stand out when reading the specs of all these types - price and weight. The QSC K series is cheaper and they weigh less.I feel for all the pain I'm hearing in this thread. I had evaluated QSCs and went with EAW RSX boxes (RSX126's and 129's). They have worked flawlessly, have a great app you can run on an IPad, and sound fantastic. They are more expensive than QSC equivalents, but one botched gig causes more long term cost. Pay now or pay later. Another alternative worth a look are Yammie's DZR series - these are exceptional! I would have bought these if they had been available when I made my EAW purchase, though not worth switching out at this time.