Hi Daniel, I have been using an FM3a for 2 years now, cannot think of anything bad to say about it. Aperture priority is very handy to have when you are shooting in a hurry, AP lock is very handy for those scenes with tricky lighting. I used to think that a spot meter in the camera would be useful, but when I look at the results I get with the centre weighted meter I realise that with a bit of experience results are great.
With ttl flash and a PC socket it will take all the guess work out of flash photography, I use an SB22, and with an SB27 you will have a little more flash control than I have. The fill flash function on the camera is very good as well, if a little difficult to find in practice.
I use a 105 f2.5 Ai, 50 f1.8Ais, 28 f 3.5 and 70 - 150 E series lense, and the results are excellent. Any duff shots are always my own fault.
The outfit is small, compact and intuitave to use, there are no menus to scroll through to adjust settings etc, it is a tough little camera that performs well in all sorts of weather, I cannot praise it enough.