I’d take the JBL PRX735 over the QSC KW153. I find that the JBL PRX line has better sounding limiters than all of the QSC K and KW series stuff. They kind of squelch the sound more at the loudest (near clipping) volume levels, whereas the PRX dj equipment speakers stuff sounds smoother even close to clipping. The K and KW stuff does have a clear and airy sound at low to moderate volume levels. The PRX735 is about 10 lbs lighter and has fans on the amps to keep them cool.
I started with active speakers by EV’s went to Yorkvilles and now JBL’s in the past 7 years. If you’re a DJ every weekend sometimes doing doubles, it will get heavy, and the DJing becomes work, not fun and enjoyable. The EV zxa5 are very heavy, QSC KW sound very good but they are heavy too. I’m on the line with JBL PRX 700 series because they are light, durable and have a very good Punch. I purchased them the end of july 2013 and they are great.