The thing most people neglect when bareshafting is the fact that having no fletching on the arrow moves their FOC way forward. You need to wind a couple of wraps of duct tape around the back end of the bare shaft to correct for that.

Other than that, I think bareshafting is as good as paper tuning for establishing a starting point for a good tune job. Probably a little better for fingers shooters than release shooters though.