The block, conrods and pistons are meant to be stronger but there is no evidence that indicates it is the case. The block number is different to that of any other rb26. The turbos are the same size but have steel wheels.
Larger oil cooler - this is not true since a normal gtr doesn't have a oil cooler at all however there is a huge nismo oil cooler. The suspension is also apparently slightly tweeked so the ride is a little firmer.
No radio thus no antenna, no air con, less sound deadening, no rear windscreen wiper, no vanity mirror, carbon fibre rear wing and front carbon fibre undertray etc.
They were only released in white.
IMO they should be around a $15-20k premium over a normal V-spec, that is if u can find one.