pros:
-get your room number before arriving at the resort (in most cases anyways)
-bypass the lobby altogether.
cons:
-none that i found.
60 days out.
well you can make room requests at time of booking and then you can also make some requests during online check in. for example at POP you can select one of the decades, whether you want lake view, which floor you'd prefer to be on...
you can also request that your room be ready as early in the day as possible if you are arriving early in the day.
just note that if you check that box it does make it your most important request so they may not give you your other requests but they will certainly try.
in april i was able to get my room number texted/emailed to me while on DME and i arrive at POP at about 9:30am and went directly to my room and saw that i got everything i requested including the early arrival, 50's section, and lake view.