Robin Smith , Aug 25, 1999; 05:52 p.m.
In my opinion a waist level finder with 645 format is hopeless. If you want 645 then you really need a 90 degree prism. To some extent this is why the 'blad has one (for shooting with the 645 back) as even a 45 degree prism is hopeless if you are shooting verticals. If you want to use a waist level finder (they are nice, but not for the whole time necessarily) then buy a 6 x 6 or a RZ67 with 645 back or perhaps the Rollei 6000 series which also may have a rotating 645 back, I think.
Metering prism are always nice and good for fast action or when you want to be quick and efficient (weddings etc.) but otherwise you can be surprisingly quick with a hand held meter. A separate meter is very good when you have the camera on a tripod (a lot of the time in MF)and probably better as you can continue to meter usefully without having to repoint the camera. This is particularly the case when shooting a landscape and when the lighting is not 'behaving'. They are less good when taking pictures handheld