It depends on a lot of things. I would say we are a little over 50% on getting requests. You see some posters that get them all the time but recently have seen some that say they NEVER got their request.
I would say it depends on:
1. Time of year - how crowded the resort is so how flexible can the room assigners be.
2. How specific is the request. The more general, the more likely it can be fulfilled. If you ask for a specific building that is pretty general. If you ask for a specific building, specific floor, facing a certain direction that is getting pretty specific.
3. Luck.
I don't think even the most experienced people on these boards know enough of the statistics to be able to say how many requests get answered.