One thing nice about the FM2n is that you can still buy brand new focusing screens. I've got an E3 (grid) screen in mine; I'm not absolutely sure, but it seems to affect the meter slightly, about 1/3 of a stop. The E3, B3, and K3 screens were made for the FM3a but they will fit in any of the FM/FE bodies.
Overall I prefer the F2 to the FM2n, but the latter is still a lovely camera.
I know many of you have been on the edge of your seats but, I finally decided on an F2. I installed a a ground glass with a grid and have a magnifying waist level finder. The remote shutter release cable was a breeze to find (and cheap). I went with the F2 because of the dedicated MLU, the fact that it has a mechanical shutter and interchangeable finders. I'm in the habit of using a handheld meter so, not having a metered prism is not an issue so, no battery at all do worry about. The only thing I need is that little cold shoe mount doo-hicky so I can use my cold shoe mount bubble level.
So, I'm pretty happy.
Cool, I hope you like it! I use my F2 more than my other cameras; I want another one to keep different types of film in.