Looks alright to me assuming they stick to their word on the body work. Has it had a clutch change? If not it might need one hence the low price.
GT model differences I believe are forged rays alloys, leather seats, bose sound system, cruise control and heated seats so if you can live without these or you plan to replace the wheels and seats anyway, cant see a reason not to get it.
I love S2k's, thought about getting one also but I was lucky enough to go to a show room with both a 350z and an S2k next to each other. I looked briefly at the S2k but they pretty much had to prise me off the 350z.
Your choice buddy but id go zed based on your previous posts and my personal opinion