For a pure movie system I think you would find the latest PB12 goes noticeably deeper than the EP350, and you probably would prefer it, at least in a larger room.
On the other hand, the EP500 is a totally different beast from the EP350... it plays deep bass more accurately than the SVS, is reported to be one of the better ported subs for music, has tons of power, handles overdrive situations much more gracefully than most subs (ie you can crank the volume and not hear your sub making "grunking" noises), and is still small, nicely finished and matches all your other speakers.
But, of course, it is more expensive too. Welcome to the slippery slope
>>the SVS was a pretty good step up in quality
I probably don't need to say this, but we're not talking about quality here, just "design philosophy". The EP350 is nice, well balanced subwoofer that does music and movies well, which is what most people want when buying a system. The SVS plays deeper (and probably a bit louder) but sacrifices size, finish and musical performance. They are both high quality subs, although I'm sure Axiom and SVS both feel their own products are higher quality
