I happen to use Nikon - because my first new SLR was an original FE. Liked it, (still like it for street shots) and stuck with em. I'm sure that if my first new SLR had been an AE-1 I'd be using Canon. As for weather-sealing I have an FM, FE, (yup - that one!!) F3, D 90 and F-100. They are all totally black from a fire - huge amounts of very hot smoke from burning plastics. This happened one year ago. Last week every one of them powered up and the shutters fired. Just got to find a way of cleaning them, but I'm betting I'll be using them.