if your wantin some SQ woofers look at Fi Q, Stereo integrity mag (the new proto is lookin very impressive), anything Focal, SSA is coming out with a SQ oriented woofer. Some of RD's woofers are suppose to have nice SQ. RE XXX, RE MX, ofcourse the W6V2 is very SQ oriented.
JL, RD, SI, ID Max, Diamond, and Adire come to mind off the top of my head. W6's from JL, Classics from RD, Mags and BM's both sound good from SI, D6's from diamond, and Brahmas from Adire were the actual subs I liked.