If a Plus is an option, I'd step up to that for sure. It is worth the upgrade. I do like the cylinders also.
would like to but in Australia we pay double what you pay, the PC+ 20-39 is around $1899 (AUD).
I am paying $1275 (AUD) for the PCI 25-31, but it's cool, will have to deal with it if we want the quality of SVS.
In OZ we have only one importer DeepHZ Audio, they stock the PCi 25-31, PC+ 20-39 and the PC Ultra.
Mind you the PCi 25-31 that they import are tuned to 22hz, so there really 22-31, lol.
Plus my place is small, 370 W x 350 L x 300 H, so i think the 25-31 is sufficient.
If i get a bigger place later i can always get another.