Old film cameras are better to learn on, but it is not because of the film, in my opinion. It is because you have no choice but to use manual controls. Learning manual control of any camera, be it film or digital, is, in my opinion, the best way to rapidly improve as a photographer. Granted, once that rapid stage of improvement is past, it takes longer to develop a good eye, but this discussion is about learning with equipment, not learning with the eye. If a person has the discipline to put a digital camera in full manual mode and keep it there at all times, a digital camera is a just as good, if not better, tool for learning. I am a bit fuzzy on bene's level of experience, but spending 500 bucks on a D40 and a 35mm f1.8, as previously mentioned, would be a good starting place IF bene can manage to keep it on full manual all the time, even manual ISO. I would think that, starting out, auto white balance would be ok though. The important thing is getting an intuitive grasp of apertures, shutter speeds, isos, the relationships between them, as well as things like reading light meters, manual focus, etc. Bene, good pictures can be made with nearly any camera, and bad pictures can be made with any camera, bar none. Before you go shelling out significant loot on an m camera and m lenses, regardless of manufacturer, pick up something like a d40, or a pentax k1000, or a fixed lens rangefinder. Something with a reasonably fast normal prime lens, like 35mm on a crop sensor digital, or something between 35mm and 50 mm on a film camera. Until you can get the best out of a camera like that, you won't be getting your money's worth out of an M8 or ZI.
As to digital black and white, it is making leaps and bounds. All of the black and white on the first 8 or so pages of my flickr page linked in my sig is digital, processed with silver efex pro. I am thrilled with the results. I have a couple issues with some stairstepping in a few of them, but that is because aperture 2 doesn't play nicely with compressed .nef raw files.
Arguments for film can certainly still be made, and they are still certainly quite valid, but the arguments are getting steadily weaker. On the other hand, I think the M8 is a pretty lousy camera. My answer to the question of M8 vs. ZI is neither. Get something more basic and inexpensive, keep it in full manual for every shot every day for a couple years, and then score an M9 when you have saved up the money, if you feel you still want an M camera.
