I have yet to have any issue with it in actual play, it just means there's less narrative focus on setting up camp and doing watches every night. I don't really notice it as missing because the gm kind of skips over narrating sleep. Also speeds up travel, because you don't have to go over watches every time and all that.
It felt odd when we chose to take a week long boat trip after one or two encounters (instead of going over land), that it didn't get a heal up or daily's back. Apparently we spent the week being very depressed.
I think most games I've been in that have a lot of travel end up with a set watch order and the DM only stopping the fast forward when something happens. (Like the fast map traverse in Brisco County Jr.).