@holmz
Thank you. I'm always tweaking, but getting the Quatros was a milestone when I got them. They were my price/performance bullseye for "forever" speakers, and I had owned 1Cs and then 2Ce Sigs before getting a really good deal on them from here. Then they had to go and add a CT version (sigh), but that's another story--ha. They are fantastic, though.
Vandersteens actually make really great surround systems due to their spaciousness. You can honestly just run movies two-channel, and they sound great. Also, their surrounds (VSMs) are made to be wall-mounted and look very sleek when done so.
To your comment about the Xover frequency, though, it HAS to be correct on any subs or else it will damage them. Just so you don't ever do that if you get some. Other passive models can be toyed with, sure.