I've bought a pair of these to run for tactile feedback on my sim racing rig. They are supplemental to a couple of Earthquake MQB-1's, which whilst superior in my opinion, are limited in range (15 to approx 70Hz). The Mini LFE's are used to take the higher frequencies (50-180Hz in this case), and handle these well, but they will bottom out with an unpleasant rattling noise when pushed hard and low. Overall they add a nice balance to the feedback, allowing me to feel road impacts, RPM, and engine vibrations through the full range.
I have not used them for music, so cannot offer feedback on that aspect.