I am at the early stages of deciding whether or not to pursue a svs subwoofer. I am looking at the pb2+ and the pb2 ultra. The diff. that i see is the 100 watt diff. and the diff. drivers. Is it worth the extra money for one of the ultra's. Also, has anyone on these boards personally heard the diff. of these two. I would like any info. you can give me. I have done search upon search already. I have found some very good info., but none that refers to this, that i can find.