Any Nikon SLR since the F5 has essentially the same control layout as a modern DSLR. The F4 is considerably different, with a modern body design, but older style knobs and switches (my personal preference).
The F4 is truly the jack of all trades, and takes pretty much any Nikkor lens ever made. It'll matrix meter manual focus and AF lenses, it'll use pre-ai lenses no problem (something the F5 won't do), and it can use G lenses no no problem. It's my go to body for just about everything. You can stick just about anything on and it'll work flawlessly. This camera traveled all over Finland, through Russia, Estonia, and back here to the USA with me, and is still not giving me any BS in terms of operation. I love the Cs mode on it too, which I use quite often when a noisy shutter would distract, or alert my subject. The ergonomics and general design of the camera are ingenious. In terms of sentimental value, my F3 is the one I hold dearest to my heart. But for unwavering output and universal compatibility, time after time, my F4 gets all the attention.
The F6 is basically an F5 with the vertical grip sliced off, which is to say it's basically a D1/2/3 without the vert grip.
The F5 is a more powerful camera, motor wise, however. The F6 is a more refined, subtle piece of gear.
You haven't experienced what 35mm film can do, truly, until you've gone and shot a roll of Tri-X or Ilford FP4+, developed it, and enlarged it yourself onto at least an 8x10. Grain is beautiful, noise is not.
Alpha, you and me think in reverse :), I grab my digital when the shot isn't that important, or if I'm just going out for a bit with some friends, but as soon as I'm working for myself, or on a project, out come the film bodies.
Kanuck: my bag, on any given day of shooting street consists of:
Nikon F3 (I leave the motor drive at home, this serves as my compact body)
two or three lenses depending on the day, a wide for one body and a tele for the other, usually this is a 35/2 and a 85/1.4, but can vary to a 50/1.4 and a 105/2.5, a modified 20/3.5, or an 18-35/3.5-4.5. On rare occasions I carry an AF 180/2.8, but I find it a little long for my tastes and the environments in which I work.
6 rolls of film, 3x ASA 400 (usually Tri-X, but I use Neopan 400, and Delta 400 frequently as well) this covers any low-light, as I can simply push a roll to 3200 if necessary, and 3x ASA ~100 (Acros, Fuji SS, Plus-X, FP4+) this covers daylight and bright situations. Sometimes I pull back to ASA 64 or 50 if I want to smooth out the contrast in the neg.
2 sharpies, a small moleskine notebook, and some chewie bars or power bars, plus a bottle of water. All told this doesn't way that much, and easily fits in my lowepro sling bag. I can walk all day and be on my feet for over 8 hours without incurring that much soreness or aching. I also carry some advil in case I get a head ache, or a stressed back from contorting myself all day.
my arsenal is the following, however it's rare for more than 2 bodies and 2 or 3 lenses to be on me at a time:
Nikkors: AF18-35/3.5-4.5, 20/3.5, 35/2, 50/1.4, AF50/1.4, Micro 55/3.5, 85/1.4, 105/2.5, AF180/2.8
Rolleiflex Automat X (Needs a CLA, but is fine at speeds above 1/2 a second, I reassembled the viewfinder myself and cleaned the focusing screen to look nearly brand new)
Yashica Electro35 GS (This guy needs to go to the shop, I wore the advance lever padding out over the summer)