>>4346775Very nice. Those are both fun and a pain in the ass to use. If you have something to rig up a somewhat accurate external viewfinder it will make your life much easier.
The sinar zoom 2 is probably the king of MF backs. It is adjustable from 645 all the way up to 6x12, and you can change the format between shots and it calculates everything out! Pretty pricey, but really cool.