I would be tempted to jump to the Note 2 if there was no price impact.
First off, I love my S3. The battery life is phenomenal - with average use, I usually have 40-50% left at the end of the day (from 6:00 AM to 10:00 PM). The camera is awesome. There is a ton of development if you decide to go into the rooting/ROMing scene. The screen is really nice, too, and my signal has been comparable with my old Thunderbolt. In short, I love this phone.
Why then would I switch to the Note 2? It basically boils down to two things. I'm a pretty big guy (6'3") with large hands, so I don't think the size would bother me and the extra screen real estate would be nice. The second reason is the stylus. I think it'd be really handy to have that for tasks like technical sketches on the fly, and it could be pretty handy for photo editing, too. Basically, it'd be nice to have the option to have a finer input option for times when you need it.