Ted you've got some really nice lenses there, so, getting the F100 makes sense if you can swing it.
The F100 is much better built than the N80.
The F100 can meter with mf AI & AIS lenses (N80 doesn't). This may more important for me than for you, I don't know.
The F100 auto-focuses faster.
The F100 flash synch is 1/250 while the N80's is 1/125 of a second.
The F100 uses the more common AA batteries.
The F100 viewfinder shows 96% while the N80 shows only 92% of a scene.
The F100 does exposure compensation by thirds of a stop rather than the N80's 1/2 stop increments. (Third stop increments are my choice, may not be an issue for you, though.)
And lastly, the F100 weighs a little more but I relate that with added quality in this case.
I associate the F100 closely to the F5. I do not associate the N80 with the F5. So, with the lenses you already have, you'd have a really great set-up if you added an F100 to your equipment list.
I hope that helps!
Marc
Thanks all. Very useful replies. A few points to note :
1) I have a Nikon SB-800 flash gun which, as far as I know, will work with the F100
2) I don't have the cash lying around as such, more's the pitty. I'm just always looking to better my kit where I can and was wondering whether it was 'worth' upgrading from the F80 to F100.
3) Glass wise : FilmSprocket - I am with you 100% there. All my major investments have been in glass. My Nikon 80-200 2.8 was my most 'serious' expenditure in that regard. But I have the Macro 60mm prime (from new), Standard 50mm (from new) and the SuperWide 20mm too - all of which seem like great lenses so far.
4) Price wise - I think the prices I quoted where from e-Bay. Not sure now though because having just done a search again they do all seem to be >£200
I will give it some more thought and have a ponder, as well as reading a side-by-side comparison.