I have had mine for three years and love it. The only thing I dislike is when rewinding film, in particular, black & white. Damn thing disappears into the canister unless I intervene. Sometimes losing a frame or two in the process.
I have to ask though, what is 'the Armorall treatment'?
https://www.flickr.com/photos/underlord/albums/72157631605415929
A common problem with the N90 and F100 is that the grip backs on them start to break down, and get sticky. What you do to treat this is clean it off with alcohol (preferably the higher percentage version), then coat it with a liberal amount of ArmorAll car interior protectant. That has to cure for a few days, then you are good to go.
When I tried this on my N90s, I didn't get enough ArmorAll on the back, and so I started over with the treatment. Doing this, I wound up removing the some of the coating, so I'm going to remove the rest of it as soon as I figure a way to keep the little icon strip from disappearing. I'm thinking some clear label tape will do the trick.
My first observations of using the F100 are how much quieter it is than the N90s.
I've got the battery packs on both cameras, so that doesn't make much difference in the way they handle, though the one on the F100 helps it stand better.
It came with the grid screen, which is a great addition in my opinion, seeing as I have so much trouble keeping my horizons straight.
Nice improvement in AF speed, with no stutters so far. Something I have to try out is setting the focus point.
New dials and switch additions are great, especially the On-Off switch. It's much easier for me to remember to shut the camera off between locations, and less likely to be accidentally moved. Dual control wheels, metering switch, and built-in diopter adjuster are fantastic, though I wish it had an eyepiece blind like the N90s. I'll try not to lose the one I bought.
It just feels better than the N90s, with a good grip, and more balance. And it looks great too.
PF