BXDreamer,
I can only suggest you test drive a BX if you have not already. I'm just shy of 6'5" and the only time I feel too big for the machine is when I'm dismounting. That's probably because I don't want use the MMM as a step and I have to swing both legs over first. Operating it though, I never feel cramped with the hydro pedal or the seat, etc.. although I'm sure when I'm on the BX it appears to be more of a GT as I'm out of scale with it. Kind of like a smallish motorcycle I once had. I made it look like a kid's minibike!
I'm sure you'll love either choice. Good luck!
David