I own and use an F with plain prism, black F2 phonemic, and an F3. I feel that the plain F is the most refined and I feel that it yields the sharpest images among the three cameras (if my "feeling" is right, I would attribute the sharpness to the extra weight of the F along with its excellent balance and the AR-1 soft release that sits on top of the shutter release. I haven't tried it with a metered prism, but I would imagine the meter would disturb its balance.