It's a tough call. Assuming Tuberville will do better than Leach is assuming a lot. Most forget that Leach has won 70 games in the last 8 years, and never less than 8 in a season during that span. He won 9 or more 4 of the last 8 years.
It's also tough because we've seen Auburn and Chizik for a season. We have yet to see what a Tuberville Texas Tech team looks like. Until we do, I'll say Auburn wins more, but not by much.