Monster, thanks for the script, it's exactly what I'm looking for, but you'll have to forgive me, how do I actually use the script? When I run it, nothing happens. Is there a way to hotkey it?
I have set "S" as a hotkey for "Show End Result Toggle", then just with a TurboSmooth sitting on top of the stack you can toggle display on or off. Not entirely sure why you'd want to toggle increase/decrease sub-d level, surely you have a "target" subd level that a mesh is going to end up at? No point previewing at sub-d…