I'm with Bugrof on this. If it is possible, a complete cockpit greatly immerses one in the game, and adds a touch of realism. It also makes it seem more like a serious sim ...
drawing that stuff isn't easy, you know
But still, I think more would complain that you couldn't turn the full cockpit off than the amount of people that want them in
Maybe that could be fixed with a setup option of some sort. Check option A to use the TRE file with the rendered cockpits, check option B to use the TRE file with the old-style floating HUDs.
Personally, I really hate full cockpits as it massively reduces the view and makes it far harder to track targets. This problem was especially prominent when flying the Rapier (in WC2 at least, still trying to get WC1 to work properly).
I'm not sure if full cockpit screens would work terribly in the Vision engine as the controls are much finer than in the previous games (at least to a mouse user like me)