Stateside, since 2004/5 it's hard to find fuel these days that isn't E10. While my car certainly runs more efficiently on pure gasoline, E10 hasn't affected my car to any degree I can notice. And, most likely, it's been what my car has run on since its production.

You should be fine... what worries me is the proposed push for E15 over here. At some point, there has to be a point where it becomes a major detriment.