It's no suprise to me. That subwoofer is incapable of hitting low and hard....it's just a fact.
I don't think Polk paid enough attention to this bracket for many years but that's finally changed post-PSW1000, specifically with the DSW and Micro-Pro Series. You have to realize that for the most part, Polk hits a different and larger audience than those of us on these types of user/audionut forums. However, that dynamic has shrunk DRAMATICALLY in the past 5 years and people are seriously looking for blood and guts subwoofers these days.
I've been an SVS owner(4 subwoofers) for almost 5 years and am a few clicks away from a PB-13 in the next week or so. That being said, I'm real happy that folks like Mark Susskind(Polk Audio Sub & 12V Guru) aggressively fought to really sink some teeth into this area again. It's not that Polk can't make a good subwoofer, seriously...it's a speaker company, it's just different approaches to marketing in the end.
Does SVS have anything to fear? No, again design and objective BUT I finally don't feel embarrassed to talk about them. I wish they would make a beast but perhaps that's for another meeting....and another back of the room waving of hands.
Not everything you make is a winner and not everything wins a prize....that's audio.
Mark
Polk Audio CS