Lets be honest, if the final product differs from the prototype, usually is for the best, with some exceptions, I'm fairly new to this, but I think the only figure I recall seeing where the prototype was better than the final product was Igor and the final outcome wasn't even that bad at all.
The reality is, without an NRD people will PO figures they don't even like to begin with, because they can always cancel without any consequences and I'm sure that's what a lot of people were doing and SSC will get stuck with figures they'd be forced to give away through contests or mark down 20,30,40,50% to clear out space.
My thing is, practice some self control, sleep on ordering and if you like the prototype go for it, if you are a nit-picker about these figures, a safe bet would be to wait it out till the final product is out, there is no need to PO, if the figure sells out, you'll always find someone willing to sell, if you find yourself paying extra, don't blame it on the NRD, blame it on your inability to commit through a decision.