Thanks for the reply Scott. What sort of prompted my question was after seeing a promotional video of the Obsession dobs, the large 18" and up scopes look really, really smooth in their movement and part of their promotion was that they can be moved around in alt/az with one finger
Granted, I don't think I'd be out in a strong wind but thought even a slight breeze would be enough to catch on the shroud and make observing frustrating.
cheers