I would be careful about your assumption that you have a "slow" sub - unless it's a piece of crap (and yours certainly is not) there is really no such thing. Check out this article:
http://www.soundstage.com/maxdb/maxdb061999.htm
I think you have a sub integration issue that likely has nothing to do with your fine sub. Your comment about drum rolls reinforces this - I can't think of a drum roll that your sub would even produce or that you would want it to produce given your speakers. I guess it's possible if you have it crossed over at it's max upper frequency but even then I'm not sure.
I think you either have speakers that don't do what you want them to do with your kind of music at your listening levels and/or you don't have the sub integrated properly - the combination of placement, volume and crossover is wrong. I would investigate these things carefully before shelling out more cash on a sub that someone on a forum claims is "really fast" and likely will not fix your problem.