Well being the Nikon fanboy that I am, I'd say go Nikon, but you obviously don't want to

I've heard good things about the A750, and that it shares a lot of the technology of the D300, so that can only be good

Perhaps a Sony user will come along to offer more advice, not sure if any of the regulars use Sony
EDIT: Perhaps a mod'd like to move this to the "which camera" forum
