I have Nikon D70 thinking changing to D80 any body any thoughts as to if I will gain much:
You should have a good reason to change, otherwise you will be really wasting your money, that you could put towards a nice lens. Good quality lenses generally give you much more quality than a body upgrade will.
When I upgraded from my 300D to my 30D I did it for the following reasons.
1. Speed. The 300D takes about 3 seconds to wake up (annoying if your at a shoot).
2. Write speed. The 300D takes ages to write files to CF, the 30D can take and write about 14 shots in the same time the 300D does 4.
3. Better noise handling, the 30D is much better at higher ISO, very important for me as I do a lot of gig photography.
4. Not a big issue this one, but I wanted the built in PC sync socket and the Second Curtain Shutter Sync.
5. The 30D is 2Mpixels more than the 300D, which makes just about b****r all difference to overall image quality, but it does mean I can crop a bit more.
Points 4 and 5 were relatively unimportant, and I would not have upgraded for those two points alone.
Points 1 to 3 are very important to me when doing Gig/Sports photography. For portrait/landscape etc they are not that important at all.
Hope this helps,