I chose canon for one of the reasons that their bodies are made in japan vs. nikons being made in thailand. Ive had many made in japan electronics and they neve rlet me down. for example I have a RCA VCR from 1991, mad ein japan, still works, and a pioneer stereo reciever from 1982, looks new and works like new. japanese quality or atleast reliabiliy seems much better than being made in china, etc
Canon and Nikon both manufacture in Japan and outside. I believe Nikon tries to manufacture their FF bodies in Japan and their higher-end glass. I've got bodies made in Japan and Thailand. No difference in quality that I've noticed.