The newest version of this sub is the ProSub100TL. I have an opportunity to purchase used the ProSub100 (previous version). I know it has less power. I'm going to use it in a 21'X13' room with a pair of Vandersteen 2ci speakers (decent bass response), a B&W LCR600 center channel speaker and as yet undertermined rear speakers. How does the older version of this speaker compare with the newer. I can get it for about $250. Should I go for it or purchase the newer version instead?