As someone mentioned a few pages back, the manual does NOT say that 91 is required - that the 87 will be just fine. So, for those who want the option of higher performance OR better gas mileage, sounds like the 2.0 turbo is a win-win, provided you don't mind paying the $1,000 upfront cost.
To address the issue of the premium vs regular price spread, there are massive difference state to state. There are some good articles online (e.g. one from Edmunds) as to why this is the case, but my casual searching seems to indicate that states with higher baseline regular gas prices have a lower premium/regular spread, whereas states with cheaper 87 tend to have a larger spread. In other words, there seems to be less of a difference between state-to-state gas prices for premium.
If any owners could chime in, I'd be interested in whether 2.0 owners who have used 87 octane have noticed a significant performance difference? From what I've read with other turbos, the main difference is a loss of acceleration. I'd be fine with that as, as others have mentioned, I'm not looking at a Jeep for the lead foot performance abilities. BUT, if there were a massive difference in performance (e.g., low acceleration, engine knocking, etc.) I might reconsider.
as todays ECU's get "smarter" + able to adjust for variables allowing various grades of fuel. my friend commented the mid grade is a good comprise with noticeable improvement, but depending on your areas cost difference will be your choice. in my eastern pa location its +30 and +30 as grades jump. a dedicated computer tune with fuel + timing as well as boost adjustments a LOT more power can be safely made. the APR stage I tune ONLY can add over 60 ft lb + 60 hp or more depending on fuel grade!!! DI allows aggressive tuning as it quells knock, + the torque that comes on down low is excellent for offroading!! time will tell how FCA built this powerplant.