I've been running E85 in mine off and on for around 6 months, with no problems related to the fuel system stock parts. Not a lot of time, but that's been my experience. As far as the experience of the fuel itself - it's awesome. I'm back on 93 for the winter and I miss the extra little bit you get!
(Flex Fuel kits.... yeah I have some stories there... if you go that route - just pay attention to the kit you buy, save yourself the headaches and potential puddle of fuel under the car!
)