[eluser]Pert[/eluser]
While I haven't actually upgraded CI myself, I do remember version 2 introduced couple of updates, mainly easier to configure application. Unfortunately I can't remember exact details, I think there was something about routing, but I do remember thinking it made my life a lot easier.
Luckily it's easy to upgrade CI, so as Jairoh_ said, keep a back up copy and have a quick look if it breaks the app or not.