Took me about half a shoot to get used to the magnify button changing to the set button. There were a couple other buttons I had to learn as well, but that's why I sat down with the camera and manual for an hour or so to learn the changes that most affected me (no, I didn't learn the AF system that quickly and am still not a master of it but it is fantastic).
It would be nice if that rate button could be user defined. I don't get it but they seem to think it was a good enough idea, I can easily ignore it.