They've had a rough start but have had two weeks to prepare and will almost certainly bring some wrinkles and changes in an effort to turn their season around. Last year they lost to S Alabama at home by 26 before rebounding to make the title game. They have talent but do seem to be a little bit up and down (also lost by 42 at UCF last year, beat Arkansas but got thumped at home by W Virginia, etc).
As for BYU it's been a magical ride but it seems almost everything has gone in BYU's favor (like +6 in turnover margin in conference play, key video replays in their favor, etc). At some point BYU is going to have some bad luck again and it will be interesting to see how the team responds.
BYU should be favored to win this game but to pretend that there it is a forgone conclusion is crazy talk.
And I don't think Iowa State has ever won anything so I'm not sure what they are so cocky about either.