Ulw-10
For the price difference, the ULW-10 is a better buy. There's a link on the product review page here to take $100 of the ULW-10. Making it, I think, $399 vs $599 for the UFW-10. The UFW has a nicer finish then the ULW. Performance of each is on par with each other (I tried both), with an edge for the ULW for easy setup with automatic PEQ.
Niether of these are real bass monsters. If your interests include HT, I'd take a look at the outlaw lfm-1 (tried one and has lots of bass) or some of the Hsu or SVS (not tried any) offerings in about the same price range as the UFW. Music wise, the ULW or UFW might have a slight advantage on the ported subs. But, I wouldn't be to worried about that. I personally don't hear much difference until you move into servo controlled subs. Servos do sound better to me for music. All those are out of this price range.