I believe the 90 series suffered from the dreaded sticky plastic problem like the 80's. You might want to watch out for that.
The N80 while being a hell of a camera for the price won't meter with older non cpu lenses; The bs downfall of the series. That and being superseded in months by the 90 series. Thank you Nikon! I'm getting my older lenses serviced to even fit on the body (I also carry a FTN and shoot non ai's) as I like the 80 body for it's abilities and you can replace them for squat if they get damaged or stolen(?) HA. Btw they take the MB16 grip for AA's.
If I had it to do all over again years ago, I might have stayed with Pentax after my Spotmatic F. I've tested only a handful of lenses, some Nikon, some Pentax, some FD Canon and a couple of odd's and ends, and the (older) Pentax had a signature that I liked and were plenty sharp with very gradual drop off's over the range. Maybe someone else can speak to this comparison (or others, Minolta, Canon etc) with greater insight and experience. The mid-range AF Nikon's I have or had, have just not impressed me all that much at the "new" price. An example would be the F1.8 50's in the N series being good, but I don't see that in the later D series and I haven't shot the 1.4's. Personally I don't see paying more for a 1.4 unless it freaking performs at 1.4. The best Nikon I had was the AF F2.8 80-200, with alot of weight at a big price. Basically you get what you pay for.
Picking bodies come down to holding them in hand. If you have good Nikon lenses I believe your best bet is the F100 or F5. Then again Nikon has a habit of pissing off their followers over and over again so maybe you'll want to rethink your hitching you wagon to their star.