So, I want to give a full review of my PB12 plus experience, but i'm going to wait to do this over the weekend, will include many photos and video.
I can say right now that in my limited experience, which started with a onkyo 8inch HT in a box sub, then used just my klipsch towers(which sound fantastic but are limited to about 33hz, then trying the Klipsch SW15, and now the SVS PB12 plus. It took a little bit of tweaking, but I love the way this sub sounds. It just hits and lets go, I seem to hear only what I need to hear unlike the Klipsch SW15 which just rumbled the whole time. I also have yet to push the Plus to its limits, assuming it has one, the NSD may be enough for my setup but I know i'm safe with the plus, I feel like it will never let me down.
I moved my whole front stage over to make room for the plus up front but it really does not look good, the girlfriend said it would be fine if there were two subs to balance out the look, mmmmmm, tempting, haha. So I will more than likely move it to the rear corner of the room in between the two couches which I assume with be a improvement, corner loading and close to the seating area and I don't think I will hear port noise with the ports coming out the top.
Also, the girlfriend is working this weekend so I can really see what this thing can do.
My only tests run on the sub so far are: The Avengers, Wall-e, and Wipeout HD Fury on PS3(gotta love the dub step music and action of that game)
Full review coming soon