Canon S100 vs Fuji F31fd
I had the F31fd for many happy years, but when it was stolen, there was no way to get a replacement, which I was more than happy to do. After much searching around I chose the Canon S95. I'm very happy with it, and it has the benefit of RAW format which was important to me. The main thing apart from image quality though was the user interface which is excellent, but I think has been compromised in the S100.
The F31fd was a classic, and I'd still be using one if I had the choice, but I didn't so the S95 fills the gap in a excellent way. It is more, but the F31fd had a certain something. I think the S95 may have it too, but I don't use it enough to know for sure.
I think I've been very good in choosing/lucking some classic cameras from the Fuji S602Z Pro followed by;
and now the Canon S95. I think the S95 will be looked on favourably as time goes on. Especially when the follow up had many problems.
If your F31fd is still working, then great, but if it's on it's last legs, then I'd seek out a S95 before those stocks disappear. If they haven't already.