I have used an SVS Ultra as my sub for years now with my Maggie 3.6R's. I listen mostly to rock(Hendrix, Petty, Beatles) and find it fills my room with ample bass at a reasonable cost. I also own a JL F113 which I use in my Home theater, so I have experience with other subs. It is plenty 'fast' enough to handle all types of music in addition to rock, like jazz, classical and types I listen to. The only real drawback for me is the size of the cylinder(4 ft tall) which has a 14 inch footprint. I found the price from SVS sound competitive.
Happy Listening.
Rootman
Happy Listening.
Rootman