Oh my, I have the EP500 and it rattles my entire house, I can't even imagine what the 600 would do. I'd probably start the next big one here in the Bay Area with that. Seriously, I can't imagine what more bass I'd get with the 600, I have my 500 at 1/2 vlume and -5.5 db and it's in your face! I swear, the couch is moving in some scenes.
You are going to be in for a ride with the 600, that's for sure! You might want to wear protective clothing and a helmet....
And that guy with two, is he in the wrecking business? Man.....