Hi Yannick, respectfully, let me say that it’s because OmniPresence is hands-down superior to Dropbox. When editing files between OSX and iOS, I don’t have to worry about getting out of sync because it’s synching between constantly. I’ve tried to screw it up just to see if I can and it doesn’t. With Dropbox, I have to be exceedingly careful that my files aren’t out of sync and that I don’t inadvertently corrupt something by opening projects/files on two devices at once.