[AgX]

It was my first SLR back then when it was introduced. It would be my first choice if asked what analogue SLR to advise a beginner to: It has useful features, but still is not hard to understand. And there is actually nothing missing what one definitely must have.
What I miss is a is +/- correction to the exposure meter. But one can handle this via the film-speed setting, and actually this is quite a good idea for a beginner to be tought how things relate to each other.

Another advantage is the good availability including most of the lenses. Concerning lens performance these even outperformed Nikon equivalents. I know, lens tests, MTF's... I just hint at this concerning the Nikon/Canon discussion.

Concerning being bound to a certain system: with the low prices of most SLR bodies today, changing a body for another type is the least to worry about.

As already said, the lens range was cancelled in the mid-80's, but the Canon-FD bodies have one of the shortest flange/film distances so adapting other lenses is technically quite possible.