Seems opinion is split on this one. I have over the years flown models with both types and have never experienced any flutter what so ever. Mind you, I do make sure my hinge gaps are minimal and ensure all linkages are nice and solid and slop free, maybe that's the real secret?
On the subject of hinge gaps, it always makes me cringe to see some of the models in magazines that you can see daylight through the hinge line - yeeuuck!

Thanks for the input though. To sand or not to sand, that's the question ;-)

Tony