Linear SPL + fast transitions + low extension does a good subwoofer make.

I forget where sunfire's were mentioned, maybe it was here, maybe it wasn't, but if their bigger subs are anything like the Jr then the RMS power should be around 270 watts. They've had on their site before that the Jr was about 125 RMS and 1250 max. Peak of 10 times the RMS which is incredible. A store guessed about 400-500 RMS for them.

I hear excellent things about velodynes. I wish I could hear one of the higher end ones for myself.