Hi Bunkertoy, congrats on your purchase. I'm sure you will love it.
I wouldn't sweat your decision to get the SST over the SST2. A few years ago I upgraded from a pre-NRB 3B to a 3BSST. I didn't do any A/B listening test at the time. I just unplugged the old and plugged in the new(er). It was a pretty low-key event for me. I didn't notice much, if any, difference, and it was definitely not an OMG! moment. That said, I do really like the SST. 12V trigger, toroidal transformers, better specs, no physical transformer buzz compared to the older amp, and of course 15 or so years newer.
I know that Bryston keeps improving their amps, the specs prove that, but for whatever reason, the difference in sound between the amps wasn't really noticeable to my ears. Maybe my speakers and source just aren't up to the level needed highlight the differences? Maybe the fact that the old 3B had been recapped really helped it? or maybe just because I'm getting old and can't hear above 13Khz anymore. Not sure.
Anyway, please do post back your impressions. Unless you notice a massive difference between those models, I doubt you would notice a difference between the SST and the SST2. 3 revisions vs 1. It's for you to determine. Enjoy.