I might still be trying to decide between 600/800/800e if not for the Nikonusa holiday deal. The freebies made the effective price less than what I paid for a D7000 a few years back.
I am very pleased with the 600 and have no regrets. My pro/con list was similar to others here. I doubt that I would have regretted getting the 800 either. If there was an immediate need then I might have just resorted to a coin flip.
But NAS can be relentless. So, here's hoping Sendai matches that Christmas spirit with the upper lines.