If you include Starr in that sentence I'll agree with you. The top of Starr is more difficult than anything on CR. The skiable width for the first 30 feet or so is as narrow as Rumble and MUCH steeper.
I would definitely agree on Liftline and National. They really should be left ungroomed. I don't think ANY double black run should be groomed outside of recovering from a freeze / thaw / rain event. Not even a bail out lane.
Stowe has so many great cruising runs as it is, I see no reason to groom Liftline and National. I suppose they do it just so people can say they've skied them.
It all depends ont he conditions. You can't go wrong with either palce if the snow is there. I dont remember CR being anything but a lot of fun. Stowe had a few stops where I had to slow down so I did not hurt myself.
I quoted this because. IMO you should not be able to groom a double diamond. Single diamond OK. Double you should not be able to get a groomer on, not because it could't use a grooming but beacuse the terrain is to steep and knarly.