Ok that's important input. Cause It's gonna see some heavy use. I think I'll go for a doug kennedy split back frame then. They look really nice.
By the way, this may be a stupid question, but how do you make sure that the negative is where you want it to be on the paper, when you are using 5x7 film and 8x10 paper? It seems to me that there would be a lot of fiddling with a split back frame, where as on a paterson proofer you just put it where you want the negative on the paper, and close the hinged glass.