The SSP is shorter. The table is smaller, physically. Mike already pointed out the difference in how the bin/flame access is a little unwieldy in the SSP. I have been using a Gen2 for a couple of years and the charcoal stays dry in the bucket, although I also cover. The bucket is bigger in the newer style, but it also occasionally flops open on its own, which is annoying. I like the handles for wheeling around the SSP a little more than grabbing the table on the Gen2. Personally, I've never found the top of the plastic performer to get any fuglier than a stainless steel surface, and with a dollar store degreaser spray and a paper towel wipe down mine looks fine. I wouldn't put a just emptied chimney on the plastic table though. 5lb tank more economical than 1lbers...if you can get it filled/re-certified.
Basically, what do you like? I agree that you should try both (c'mon, you can always squeeze in one more grill). I'm sort of going through that myself. I've had a disassembled SSP for a while but just brought home a black SSP and will see how it feels in somewhat regular use.
Good luck. Keep us posted!