The F's meter is not coupled - no Rolleiflex ever had a coupled meter (at least not in the sense that it would give you exposure automation). But the meter in the F is an improved design over the meter in the E. The F also has interchangeable viewing hoods, so you can use a prism on the camera if you want. Later model E's (the E3, and I think MAYBE the E2) also have this option, but they still have the older style meter (which is highly likely to be dead by now). I have a pair of 2.8 E Planar bodies, and I love them to death. On one the meter is marginal (it's good for confirming sunny 16, but you can figure out exposure under those circumstances anyway!), and the other one it's completely kaput. To the best of my knowledge, the lenses and shutters are identical, though. There MAY have been an improvement in the coatings, but not that I'm aware of.