Actually, I think it is a good choice. Of course, I thought Donny Osmond would be perfect for the role. Ashton plays a smug, full of himself character just fine.
It is all the other charatcters that make the show funny. They play off charlie's character.
I am sure I will watch the first episode with Ashton, just to see how it goes. Even if it anly goes for one season, they have lots in the can for syndication.