Alright I read this whopping thread so I get to contribute my useless opinion
For the record, I like the regular 370Z body style and wheels over the Nismo so spending less was a no-brainer (s'why I bought one), but if you're into that and/or the parts then hey, it's already assembled, better warrantied, and a bit harder to find than a regular Z so go for it. Personally the Nismo spoiler is the only part I'd consider.
Are the upgrades worth the money? Probably not but depends on if they're exactly what you want. I think that the fact we are starting with THE BEST cheapish sports car on the PLANET and talking about value is tainting the discussion. Improving on perfection is a tricky business.
No matter what compromise Nissan came up with for the package lots of us would still not think it was worth it (unless we can get that GTR engine!).
My bottom line: As long as it has a Z on it, it's okay in my book
