This is essentially the same group of teams that allowed the SWC to fall apart. I remember how that shocked the college football world- although we did get our Cotton Bowl from that mess. I expect the same may happen to the BIG12.
So while I think we should go if an invite is offered, I don't think it's a slam dunk decision.
If we had stayed in Nauvoo BYU would have been in a P5 conference 30 years ago. We are stuck in the west with only the PAC as neighbors.