You will hear many opinions of the Mamiya AFd system. Some valid, some relatively retarded. Here are my retarded and valid opinions of the Mamiya AFd system.
Lenses: you hear people bitch about them. Don't believe the hype. The reality is that they are great great lenses. They are different than German lenses which have too much micro contrast. They have a really nice OOF rendering. Their color is real nice. They are pretty contrasty. The new zooms are supposed to be good. I only shoot the fixed focal length lenses and all of them are fantastic. They are as good as anything out there at F4.
Bodies: The best thing I can say, as far as the AFd and AFd2 are concerned, is that the bodies are light and handle like an slr to a degree. This I like. The AFd's AF is like a Nikon N2020 from 1989, or like a Nikon F4s when the batteries were about to die. The AFd2 is better. The AFd3 is even better. The AFd3 feels better than the AFd or AFd2. Much better switches, better grip.
The viewfinders are pretty good. Not as good as the H series, but better than the Contax. Better than the 1ds2.
Flash sync: its 1/125. So what. If you shoot outside with strobes, don't use this camera, or work around the problem with ND filters. The flip side to the low flash sync is the high shutter speed of 1/4000. When you shoot at 2.8 in bright light at iso 100, 1/2000 is not uncommon, sometimes 1/4000 really is needed.
Good luck with your purchase.