I wanted to see how the D600 which is a full frame would compare to the supermoon shots I'd taken last month with my D90, a crop sensor. So, I waited until the sun had cleared the trees (which was at 1:15 a.m. last night), went down to the beach, with camera on tripod, took several photos and then cropped the one that I thought was the clearest to clean up in Nik Suite. It's okay, but I think the crop sensor may be a better choice as the 300mm zoom is more like 400+mm.
@amandal Thanks Amanda! For this and your other views and comments. The hard part of the moon shot to me is the focus -- I can't see without my glasses but with them, I can't focus very well. Once that's in place the rest isn't too bad.
Yes, the crop sensor is the better choice when taking moon shots. As for focus, use live view and a magnifying glass or jewelers loupe. Seriously, that's what I do.