I use Gallo Micros with a PB10-ISD. Unfortunately, my receiver only has a 90Hz crossover setting, so there is a slight frequency gap. However, it sounds pretty smooth, as long as you aren't doing a frequency sweep, which will make the gap noticeable. The PB10 is close to +/- 3dB to 120 Hz, or so, which helps. The only thing I've really noticed is that you have to be very careful with calibrating (mine's done by ear at the moment- need to pick up a SPL meter), as the large sub can easily overpower the small speakers. I run movies 3-9 dB hotter than with music, depending on how loud I'm watching the movie (actually, until I get it calibrated, music may be 3-6dB cold).
Edit: If I were to buy a new sub, I'd probably go the way of a Rocket UFW-10. The UFW-10 doesn't have posted upper frequency specs, but the UFW-12 has a frequency response of 23-220 +/- 3 dB. The SVS is great, but huge!