I learnt on a Pentax S1a and moved to a Nikon F80 about 3.5 years ago. Everything on the Nikon just feels right and I *never* have to waste time looking for anything.
My friend has a Canon EOS 30 and the control on that just don't make sense to me: Reach all the way over to the left to turn it on?! Why, when you could have an on switch right next to the shutter-release? And why have exposure compensation on the rear thumbwheel where it's easy to knock so all your shots come out overed?!
It seems to work for him, though. I suppose the main thing is to find a system you're happy with and then hang on to it for dear life!