Better. Butch is a better recruiter but Gruden is a better coach.
I don't think we have the data required to reach either of these conclusions.
Jon didn't coach long enough at the college level to have a great feel for how he'd be as a head recruiter at a program. Butch is absolutely awesome, but you have to know both sides to measure them against each other. We don't know one side.
As for measuring their "coaching" skills (recruiting is a part of college coaching, but I know what you meant), Jon seems to be a very bright Xs and Os tactician. His record as head coach is spotty, very roller-coasterish, but a big part of that seemed personality driven. Would he have the same spotty results at the college level? We'll probably never know. Butch, we're not positive of either. I personally think his success in years 2 and/or 3 of each of his previous HC jobs (CMU and Cincy) are pretty solid proof that he's an excellent Xs & Os strategist & tactician; others on VN disagree, and are waiting to see him prove it at Tennessee. Bottom line is, we don't have enough data on either of these guys to decide this one, either. Not really.
Would Gruden be great at Tennessee? No clue. He's a bright guy with plenty of experience in the game, but who knows if he'd be a good college head coach? Answer: no one does. Too many unknowns, answer indeterminate.
I'm just happy as hell that we do have Butch, and--at this point in life--wouldn't trade him for anyone on the planet. Not Urban, not Nick, not Pete Carroll, not anyone living. The General would have to rise from the dead for me to start calling for a pink slip with Butch's name on t.