I hate small subs. My sunfire actually danced around when pushed hard. To get good performance out of a tiny box is hard. Also, even though they are small, it doesn't mean that you can just "hide" it. Shoving it in a corner or under something else will hurt the sound.
I had much better sound out of an 8" energy than the sunfire. The energy didn't try to compensate for lack of size or power. However, once going to a 15" velodyne, I'll never go back.