Andy_K 

I'm not convinced the Cannondale high collar really helps much. The pivot point is still the top tube. I think the high collar just offers a false sense of security. Or takes away the manufacturers "room for error" if you prefer.

I'm picturing the forces kind of like this:



And the collar above the top tube would be like having another kid on the other side of the see saw trying to hold it up from the bottom.