Other subs are loud, but they don't have the thump the MTX subs have, for me MTX subs are definitely the best. I'm using an Alpine MRP-M500 at 2 ohms which dumps up to 500 watts RMS into the sub, I've tried it a few times at full volume and it sounds great, though my ears can't take it for too long that loud =).
Use to have several of the older thunder 8000s back in the day. Now I have one of these 12 in a sealed enclosure in my g8 hooked up to my factory radio. This thing hits tight and clean, pounds more than what I was looking for! Looks of good quality an hopefully it holds up in the long run like my older mtx. Another great subwoofer by mtx.