Just my opinion, I have spoken witn Ron at SVS in detail about the driver(s), The PC+ is a "substanial" improvment over the pci (standard) driver. There is not much cost difference. While still costing less than the ultra driver. The ultra is better, but to a "much lesser" degree of impovement. The 20-39 (in the middle of the 25 & 46) would squeeze out a little more spl, and still goes to 16 hz with port blockers. IT GOES REAL LOW. The 20-39 PC+ is still a huge structure, not as big as the 46 of course, but given it's size it will play as low as you would want to go. I just think the 20-39 is a little more diverse, and a little less cost, take those bucks and improve the driver IMO.
