I think a lot of people REALLY like Wegher and WANT him to be the better back, but right now that's not the case. (Did anyone see the RB thread following the Wiscy game??? WOW!!)
Truth is, A-Rob is running with more power and better vision right now, and he's been able to read the blocks much better as the season wears on. Though the speed appears to be on Wegher's side, A-Rob has very good football speed and seems to get to that second level pretty quickly too. He's seeing more of the field and handling the punishment better at this point.
Regardless of why (redshirt, blocking, play-calling, weight, etc.) it seems that A-Rob can handle the brute force of the Big-Ten season, but Wegher definitely is a great baller!! We really need them both to perform to the best of their abilities. I like the rotation, as long as they can both continue to produce.