I'm posting back to state how I like the Polk 6000, which ended up being my purchase. I will post a disclaimer that I have not tried any other soundbar.
As all know, of course this doesn't replace a true surround system.
It is much better than the speakers on the TV. The soundstage is wider, and the sub is respectable for it's size. It gives a little life to movies that would otherwise be pretty dead with the TV speakers.
It's not a home theater experience, but it is an improvement.
I'm satisifed with it given my circumstances (wasn't going to have a seperate receiver, and it had to be a small footprint).
I personally use the TV speakers on high treble, and the the POLK does everything else.
I'm happy with it for what it is - an improvement that gives a little bit of life to sound.