SVS PB13-Ultra?

Hello all,
This is my first post.

I'm currently runing the following setup:
Denon 4308ci
Phase Linear 400 Series (thing is an antique, but sounds great!)
Definitive Tech BP30's (quad 6.5's, bi-polar)
Definitive Tech 2002 Center
SVS PB13-Ultra
Polk FXi5 Bi-Polar surrounds

I'm considering replacing the DT CLR's and came across an astounding number of positive reviews of the Sierra's.

Has anyone paired the Sierra's with the SVS for Stereo 2.1 music listening? I know a lot of people say you don't need a sub, but I'm working in a very large room (4400 cubic feet), and would think I'd need some supplemental bass, maybe at 60Hz on down.

Other speakers I'm considering, but need to demo are: Salk ST's, Dynaudio Contour S 1.4, Paradigm Studio 40.