That's what I always do. In fact, it's why I usually never fly in Arma 2 because I never have the stick connected when I go in and it takes too long to exit, connect it, calibrate, reload, rejoin server...
Anyway, it took me 19 hrs for DS1 and 16 for DS2, so the sequel was a little shorter. I get the feeling DS3 might be shorter yet, with the emphasis on co-op indicating they plan on you replaying the game multiple times.
Not that the first 2 aren't that way as well. Like many RPGs, you can replay the game a 2nd time with the same "character" at a harder level, but I've yet to do that.
The Jedi Master