BYU should not tie its long term fate to a conference that treated it so poorly for so long. You shouldn't cite ephemeral power rankings as reasons to join the MWC.
The AAC has better long term potential for BYU, although it is still an admission of failure. I'm afraid that the fact that we are even debating which mid-major BYU should join means: a) Indy isn't working; b) BYU is not going to join Utah and TCU in the majors.