This just in:

You need to get the second woofer. It makes a world of difference in the modern dance music. There is plenty of volume and clarity in the midrange and high range, but you really need the extra punch from a second bass cabinet. You can use the line out and feed the bass amp of your choosing,k but these babies are so small and EZ to stack - for the extra $3bills..... go for the 100% Bose setup. It's a joy to transport. A joy to listen to, and a real kick to look at.

I made one more observation - if I were a full time DJ, I'd have a double stack for stereo and wider spread. There is NO PROBLEM filling a room with sound, but there will be more "presence" on the dance floor with a dual stack. Not neccisary for volume - just for close up "thump factor" It also adds to the visual image. What's another $2300 anyway?
(yikes)