Actually one thing I really love about OS X is the placement of the command key. Keyboard shortcuts like Command+Q and Command+W are much more convenient then something like Alt+f4. Keyboard shortcuts in general in OS X have been a one of the great advantages in my experience. I also switched from Linux to mac about 4 or 5 years ago. At first it seemed very awkward. I think any change like that would be, but I was instantly appreciative of how seamless the system worked overall, and how much less I had to mess with it to get it to work right (Like I said, this was a few years ago). It's not perfect, though. I would suggest that anyone who is interested in making a jump to a new OS to try and get their hands on it before buying and see what they think.