My ND friends have mixed feelings on Kelly. In terms of impact on UT, it does seem like the least worse option compared to Cristobal, Riley or Rhule.
That said, I will never forget a bizarre Kelly story from the final Charlie Strong year. During ND practice, the staff had set up one of the pieces of equipment—that padded alley where the running back pushes through several dummy pads—backwards. Meaning that the running back was essentially running into an immovable padded door.
A walk on running back recognized it was backwards and tried to tell Kelly. Kelly, shocked at the audacity of his player to question him, shut the player down and said something along the lines of “it’s not, shut the fuck up and do the drill.” Running back proceeded to try it at a full sprint, bounced off the equipment and ended up in concussion protocol.
I hope he brings that kind of attitude to the SEC.