Ugh, Nissan please please PLEASE stay away from a boosted 4 cylinder platform! If you want to build a Miata that's fine, but leave the Z out of it.
I chose my Nismo over the more powerful Ford Mustang 5.0 and SS Camaro because it was/is a better overall package IMO. Squeeze out 50 more hp (preferably NA, but low psi SC would be cool too) and it would be absolutely perfect.
Not sure why people are talking about the Subaru/Toyota/Scion thing in the same conversation... different price point and entirely different performance level. Has anyone driven one? I have, and that thing is gutless!