The D300 is a major feat of camera design and for the price it's all that much better. It's operation is extremely customizable and the ergonomics are spot on.
My major complaint is that in continuous focus servo mode with automatic AF point selection the AF points in use are not indicated in the viewfinder. However the active point is indicated in continuous servo with 3D dynamic point selection and single shot servo with automatic AF point selection. It seems like a strange omission. Perhaps the cameras processors aren't up the added processing requirements.
The results in auto AF point selection mode with continuous servo are fine, it would just be nice to know the camera was focusing as you intend.
The AF has been extremely accurate in use and very capable in low light. I can't say enough good things about it.
Having redundant CF card slots would be a nice touch.
High ISO performance is credible and I've no hesitation to shoot up to 1600-ish.
It was time to upgrade the 20D's I use for social event and documentary photography. I'm not a fan of bodies with integrated vertical grips and have been desperate for a smaller body with a a high precision AF system (I loathe AF sensors that extend outside the indicated AF area) and pro build quality. The D300 delivered almost everything I was looking for in body at a price that makes sense from a business perspective when I need multiple bodies.