If they can get the combined crotch armor piece to swivel or disconnect to the bot mode's back I can see it as a flight pack. As is, I'm going to need to see the proto grays before getting too excited one way or another. It's definately an engineering challenge to have the torso stable enough to support three (of 6) large deluxe sized figures (ratchet joints, connector pegs, and integrated combined mode head; along with modern expected articulation). It's sleek enough, especially in alt mode; but I can't see how they could've made it more sleek in bot mode without sacrificing functionality of the combined mode torso. If it were a matter of prioritizing the combined mode aesthetic, I think the correct choice was made. Seeing this as a CAD render, I know the designers will have a few tweaks to accentuate bot mode features to its full potential. I'll consider this a work in progress; a nice teaser of where they're aiming in terms of functionality.
P.S. Larger forepaws with reinforced pseudo ratchet rockers - consider it if you can engineer it.