The full-frame was one thing I considered. From what I’ve researched, I could still use my DX lens but the images would be cropped down. So the megapixels from the d610 would only be 10. Have you ever used DX lens on a full-frame?
I have a Nikkor VR 18-55mm f/3.5-5.6G lens, a Nikkor 70-300mm f/4.5-6.3G lens, and a Minolta 58mm f/1.4 with an adaptor.