I'll bet it would be fearther-weight light - below Elise light from the looks of it. But probably gutless to match the low weight.
A quick check of concept cars over the previous 20+ years reveals hundreds and hundreds of roadster concepts. I can count the ones produced on 2 hands. The magic of the Solstice is that they found a way to build it, true to the concepts beauty and promise, knowing it would be a very low volume vehicle.
Concept roadsters come and go, but the Solstice is for real.
Is that a doggy door, or just a place to hang out your feet when then they get hot? How do you get in that thing? It's lucky for America that the Japanese can't build decent concepts to save thier lives.