I have tried quite a few roms for the Note and I can say they pretty much run all fairly smooth.
I am currently back to stock ICS, unrooted and all. I wanted to see what kind of differences between cooked and stock. I find that my performance is pretty much similar. I never benchmarked my phone, I just go with how it feels when I'm using it
i still get the occasional lag every once in awhile, but this is probably due to the "launcher" progs that I'm testing
The SG3 is a nice phone, nice specs and fast...but if you really like the size of the Note, then maybe you should wait a bit for the Note2 - Samsung Galaxy Note 2 - Full phone specifications