Hi. I'm a long-time Canon shooter who recently had the opportunity to spend a month with a D300 and the 17-55 f/2.8 lens. I wrote up my experiences here, in an article called "From Canon to Nikon". Please note I am not in any way trying to start a flame war or investigate the question of "which is better" (which is an insensible and unanswerable question, anyway). Rather, I'm trying to address the specific question: what things should someone who is switching expect to have to adjust to? What are the differences in user interface and the like that the Canon shooter should expect to confront if she or he decides to switch systems? I hope this can spark interesting and civil discussion on the UI and philosophical differences between the two systems. I'd be especially interested to hear from any Nikon user who has tried to switch to Canon what UI issues were particularly difficult (or conversely enjoyable) for them.