I am looking to upgrade my subwoofer and have two on my list the MX-150 MKII THX Ultra Subwoofer and the newer more powerful MX-350 MKII THX Ultra subwoofer. I know Stuart Robinson has not heard better than an MX-350 MKII but at £2100 for a subwoofer YIKES. What I am thinking is whether or not in a relatively small room, would I hear any discernable difference comparing the two. The MX-150 has only 150watts instead of the 350 watts ? The 150 is alot cheaper than the 350. Both have 2 12" woofers in much the same configuration. Newer subwoofers appear to be loading up with huge amplifiers nowaday, i.e. REL Q400E, ofcourse 400watts. At 150 watts is this regarded nowadays as a bit...how shall I say weedy by comparison ? I think the only difference I would notice would be a significant drop in low end distortion on the MX-350. What do you think ? Wonder if a dealer would let me borrow two to try it.