People are high on this dude, and rightly so because he's got championship pedigree, but you're taking a huge risk. We won't ever know the real reasons he left Florida or Ohio State: I'd bet it wasn't just because he was burnt out.
Let's not forget one Nick Saban and his disastrous Miami teams. Just goes to show that it's a rare coach that can succeed at both the NCAA and NFL levels.
If the Jags give up on him he's done, period. There were rumours about his commitment before the deal about his abusive assistant came to light at OHio State, rumors about his fragile psyche. This chisels those rumors in granite.