I started out years ago with Canon (manual focus), now I shoot Nikon despite for years the Canons probably having an edge if I were honest. I did this because I had lot's of lenses and the diference between various models is hardly ever worth changing all them and learning a new system. I think the playing field is even more level now since both makes can legitimately claim to be the king of the hill depending on what your priorities are.
Go with what you like and you'll probably take better pictures than you will with a "better camera" that you don't. Once you have bought into a system changing everything is a big undertaking and unlikely to ever be justified by the next biggest bestest camera body.
All of this of course will never change the fact that anyone using a camera with a white lens is a smelly cheese
