Before the EP500 and EP600 arrived, the HSu and SVS models were always touted as being a better deal than the Axiom subs. Since their arrival, that's not been the case so much. Granted, the EP500/600's are considerably more expensive now as well, but from everything I've been hearing their serious subwoofers.

If that's too rich though, I'd look at the Hsu offerings...especially the VTF-3 MKII.