Redline Reviews did a really nice video comparison between the 4cyl and the 6cyl versions of the Supra as well. If they are both turbo'd - I think I would still want to lean toward the 6cyl turbo instead of the 4cyl.
https://youtu.be/xPYSF328pew
I also wonder if Nissan will look at the pricing of the Supra to see where they will fit their car into the mix. A $40kish Z isn't bad depending on the performance they offer along with interior upgrades etc. As I type this - I do think to myself - $40ish for a base model Z - or any car for that matter - that is a little hard to swallow; isn't a brand new sport Z around $32k (if not less)?