There are lots of fine subs out there, but none offers the unique high level input of REL. Your power amp does not deliver linear power to speaker due to amp and speaker cross-over interaction. That's why you hear from REL owners loving their subs because they integrate with their speakers, large or small, so perfectly.
So my vote is also a REL, go for the new Brittania series which is even better than the old ST series.
So my vote is also a REL, go for the new Brittania series which is even better than the old ST series.