Good luck, and don't be nervous. (Yeah, easier said than done, right?)
If you're asking from a Buffalo perspective, have him compare/contrast Fewell's and Ryan's defensive philosophy, which is more demanding to learn and implement, which style the players enjoy more.
(The last one is probably obvious, seeing that he followed Ryan to NY. Was that move based entirely on the money involved, or did the chance to keep playing for Ryan factor into his decision?)
(Edit: or what HunkyDunky said while I was busy typing ... )