Some of the buttons and switches, such as the AF-ON and the AF-Area mode selector, have a more distinctive, easy-to-feel design than their counterparts on the D200. The overall configuration of the controls works very well, but I do have some personal nitpicks. For example, I really like the switch for the AF-Area modes, and would have liked a similar feeling control for the metering selector, to allow for thumb-only operation, as like the one on the D3.
If you're familiar with the AF modes of the D200, you'll notice that the D300 lacks the Group Dynamic AF mode of its predecessor, which allowed you to clump tracking AF points. It seems to have been replaced by the ability to choose from 9-, 21- and 51-point AF options, which essentially serve as different tracking AF-point clump sizes. The 3D tracking is only available with the 51-point AF mode, however.