I have a C220 and understand that the C330 self-cocks with the film advance, and that there is a moving indicator under the focusing screen to indicate parallax. Furthermore, the C330 has the option of interchangeable focusing screens.
Other than that, the lenses are all interchangeable and they accomplish the same thing.
Max Power, he's the man who's name you'd love to touch! But you mustn't touch! His name sounds good in your ear, but when you say it, you mustn't fear! 'Cause his name can be said by anyone!
C220 : fixed screen with a couple of parallax/exposure correction marks. Knob wind with fold out crank. Manual shutter cocking on all lenses. Single frame-mount shutter release, with cable release. Focus scale and parallax/exposure correction by plates on the left side of the bellows. Some variations without a cold flash shoe.
C330: interchangable screens with scale for parallax/exposure correction. Moving parallax/exposure indicator in the finder (remember to 'program' the focal length). Auto shutter cocking on most lenses. Crank advance and shutter cocking. Frame shutter release and 'chin' release. The 'chin' release has the cable release socket. Focus scale uses a revolving rod. Has a cold flash shoe.
When using my old Graflex, I like that I can look down into the waist level finder and shoot - no one really knows I'm taking a picture, they just think I'm fiddling with my camera. But it's a fixed lens TLR and so not much flexibility there. I'm thinking of doing street photography with one of these Mamiyas; Viable or no?