To the OP:
have a look at my signature. Yeap, I have 4 F90X! All are in excellent condition and no rubber peeling or nothing like that. Just a bit of TLC from time to time and the F90X is a beauty to operate!
Looking at the features between the F100 and the F90X, one might think they are loosing Custom Functions and few other things. Now, here is a little secret of the F90X: it has custom functions and even has a memory to store shooting data. All you need is a cable and a PC to read the camera's memory. The software is freely available from SofTalk, but the cable isn't! There are instructions on the net to make one though. Search for it and you'll find it, even if it is in French!