I don't know about the laundry, sorry!
However, I like to check in online when I have a fairly good idea of what time we'll probably arrive at the resort. That way I have a good chance of getting a text message with our room number and location in it, or the room number will pop up in
MDE, so we can go straight to our room without stopping at the front desk.
Let me make clear that checking in online does not mean we can't go to the front desk when we arrive, it simply means we don't have to go there, unless we have a question about our room that we want to settle before we enter it.