I'm sorry that I don't have the luxury of having both. So I guess for now you shold only relying on Ben. ( And I thinl he's honest ) Hope there are other who owns both and willing to share their experience. I never had under exp problems, especially since we got monitor to look.
Are you asking this to make your decision what to buy? If so, please consider rental or using from friend first -- for both camera. It's 100% foolprof.
From my D100 opinion, the minus of D100 is only you should add more sharpening in post processing. Of course there is other minus like USB instead of firewire, etc. S2 is usb too, I think. But the rest is all positive for D100.
In Jakarta, the shop could let me bring my own CF card and try the camera in the store only. And check out the result later. Too bad they don't sell Fuji S2.
Pinky Mirror Nikonians@Jakarta,Indonesia-- it's near Bali, if you don't know where it is