In the spirit of the OP, I thought I would add my experience.
I took delivery of my 25-31 PC+ this past Thursday, did a basic SPL-based calibration on Friday, and checked out a few movies this past weekend. "Darla Tapping" in Nemo was very nice as was the "23-19" in Monsters, Inc. I also watched Black Hawk down and even at rather low listening levels (it was late), I got complaints from my son who was trying to go to sleep.
But, one of the big surprises came about today when I got to spend some quality time listening to music. I was surprised at how much I was missing with my previous sub. There was so much more definition and detail in the lower frequencies. In a couple of cases, I heard stuff (good stuff) I hadn't heard before. In the rest of the cases, it just sounded better.
Of course one never knows how much of this is psychosomatic vs. a real measureable improvement. But, I'm pretty sure some of it is for real.
My system consists of Paradigm Atoms for sats and surrounds and a CC-170 for the center - not exactly high end, but not a complete slouch, either. The PC+ replaces a Paradigm PDR-10.
The PDR-10 was capable of shaking my furniture during bassy scenes (e.g. WotW, Star Wars II, etc.), but a while back, I started having a feeling that something was missing in both movies and music.
The system was originally put together about 2.5 years ago, but about 9 months ago I started thinking about replacing the sub. I did some research at that time, but decided I was going to hold off for a while. Then, for various reasons, a few weeks ago I finally decided I was going to pull the trigger and get a new sub.
So, I resumed my research and kept finding myself looking at the SVS subs - especially the cylinders. I really like the small foot print, the relatively lower price and weight when compared to their box-brethren, and since the sub would be placed in a corner behind the TV, I knew I could fit/hide a 25-31 size cylinder without too much trouble. But, I decided I wouldn't be able to hide a 20-39 or larger cylinder behind there.
That said, I was also digging what I read about the PB-10 NSD sub and it would fit fine as well. Add to that the reasonable price and I thought that would actually be the route I would take.
So, I emailed SVS and after exchanging several emails with Erik (who, incredibly, would respond to emails on weekends - Sundays included) in which I described my room size (~4500-5000 cu. ft - family room with connected dining/kitchen area - stupid open floor plans
), and the sort of levels I sometimes get to listen at (85/95dB music/movies when the family's not around), he clearly thought I needed at least the PB12-NSD or PCi. But, he also suggested that I save my pennies and get a Plus-series sub.
At that point, I thought I would get a 25-31 PCi - which is the sub that I had always been attracted to - figuring it would still be a big step up from the PDR-10. But, then I pondered this a bit more and after reading a few hundred more posts
I decided that I should see if I could swing the money for a 25-31 PC+. Besides the 12.3 driver, I also liked the idea that it would let me play with lower frequency settings using the port blockers. Well, after poking around the bank accounts, I decided I could find the extra $225 I needed for a 25-31 PC+.
But, I also decided that I would sit tight and see if a B-Stock 25-31 PC+ showed up - this would save me another $50. So, I wrote a Perl script to check the SVS website a few times a day for one to show up on the B-stock page and lo and behold one popped up after only about a week of waiting. I immediately bought it and as you can see I'm very happy I did.
Next steps consist of an Avia calibration and a RoomEQWizard analysis. And, if necessary and funds allow, I'll introduce a BFD into the picture.
I hope this helps another future shopper in their journey,