I've sold woofers in 6 audio/video stores now over the past 15 years, and there are some excellent choices to be had indeed. I even sold the Rel's in 2 stores. Here's what I find....
....I think most people's (even probabaly yours from what I'm reading) experience is that they never get the sub's set up right in the first place! (I like EQ'ing subs also as well in the right situation, like mentioned above).I've heard absolutely atrocious(?) results from the best sub's in the world!...and I've sold em all really! The set up is easliy 75% or more with bass woofers!...really! I've heard world clsss Velodyne HGS18's, Bag End's, MX5000's(M&K), Servo 15's(my fav for the buck) Theil and Wilson mega buck woofers sound horrid incorrectly set up!!!!...time after time, after time. And you'd walk in and hear the system with them in place, and say "why would I bother?!"
Anyway, The Rel's are potentially very tight, accurate sounding subs. I like em better for music myself. But that's me. For the money, for HT dubties in even large rooms, I'm a fan of Paradigm Servo 15's, Earthquake 12 and 15" sub's(yes, very good), M&K MX series in the right sized rooms (in multiples even), and a few others for not so much bucks. I know I can set these subs up for world class restults sonically. more expensive Revel B15's, Infinity MTS woofers, and more expensive offerings start diminishing returns I find.
Heck, I would never buy a $10k subwoofer!...ever! There's much better results to be had in the hands of a skilled system designer with multiple lesser expensive 500-1000w+sub's out there! I just don't see it.
IF I was running a mostly music first system, I would buy a Rel at the right price, sure. I wouldn't go there for dedicated HT though.
good luck whatever you get