It seems this thread was an interesting one. Actually I'm so glad with all your diverse replies, this is exactly what I wanted, to hear as many different opinions as possible. In my country we use to say: "discussion is knowledge's mother"
In summary, I think it's quite clear that my 30" inseam is not a problem (at all) to go for the F800, Whichever option I choose to compensate the lack of height, such a low seat, playing with the suspensions... or a legs surgery
Thanks a lot for your replies, I plan to order the bike soon so I'd get it by next April...