Hey,
A thread that I can answer definitively. I have both an FM2👎 and an F3. For the F3 I have both the HP viewfinder and regular finder. Here are my thoughts:
If I had to choose one camera it would be the F3. I find that having aperture priority there lets me shoot faster in situations that I don't have time to manually set exposure for. You can always set exposures manually if you want. Also it allows for Non-AI lenses to be mounted and stopped down metered, opening up even cheaper excellent glass. I can't say that the HP viewfinder makes a whole lot of difference to me either way. I do wear glasses and sunglasses sometimes when shooting but overally I probably like the DE2 (?) finder with the slighter greater magnification factor. It's also cheaper to get with an F3 for some reason. Finally the heavily centre-weighted metering acts effectively like an spot meter to me and I have grown to rely on this even more than any matrix metering I have ever used. It is uncannily simple and effective. Bright/Dark scenes and subjects you'd just compensate for manually anyway.
I like the feel of the F3 a bit better, it's a little heavier and therefore a bit more stable for handheld low light shots and the little grip on it is effective.
In praise of the FM2👎 - it is lighter and more compact for a kit. The viewfinder is every bit as nice as the F3. It comes with a split screen focus (not interchangeable) that I find a bit easier to use than the focusing screen I have on my F3 (the middle region just goes in and out of focus). I like to shoot with the FM2👎 when I have lots of time to setup and to force me to think about exposure. It is more fiddly and enjoyable to use when you're in that frame of mind. The LED metering system + 0 - is pretty effective and useful in the dark, some people prefer match needle metering, you get used to it and it becomes as quick as manual metering can I think. I also take out my FM2👎 out in the rain and wouldn't hesitate to use it in the cold
I haven't noticed any issues with the FM2👎 in terms of shutter speed accuracy. It does have a faster flash synch speed.
I'd imagine an FE or FE2 would be sort of an in-between best of both worlds (or go for broke and get an FM3a!). I think the battery issue isn't practically a problem with an F3. A spare set takes up little space and compared to digicams batteries last forever.
Hope this helps, feel free to email me any questions at aanandi AT gmail DOT com
Cheers,
-Amit