I have been burnt by the online check-in thing too many times in the past to bother with it unless I have been pre-upgraded already. Despite that spiel about being first in line for an upgrade or whatever, the half dozen times I did use it, I ended up remaining in that exact room, despite potential upgrades being available when I arrived at the hotel, and in one instance when I questioned this, I was directly told "oh no, we can't change/upgrade your room now because you've already checked in online" This obviously completely contradicts the promise given to get you to check-in online, which has me feeling a little scammed. From what I've read on here, I'm not alone in this experience either.