The VR10 (5.25" woofer, 5.25" passive radiator, 3" mid, 1" dome tweeter) is a kick-butt center channel. It was replaced by the more recent VR-MC (primary difference only being the more "deluxe" cabinet with cherry woodgrain veneer), which for a smaller center, had some SERIOUS horsepower.
Should work with a wide variety of speakers. Especially with Advents, KLH, Boston, EPI, Genesis and the like... but, we've even used them with Tannoys and such, and they held their own...
Regards,
Gordon.