I've had good luck getting very close to what I've asked for.
Most recent stays (July) were POP and CSR Gran Destino Tower. At POP, I requested ground floor room in building 6, and I think I was maybe 2 rooms away from what I requested. Gran Destino info is below.
Here's pretty much my entire history of requests!
Got exact room I requested at AS Music (twice!) I really don't care for the layout of this resort, so getting exact room made it easier to stay there.
I've gotten the same building requested at POP multiple times. The one time I didn't get near what I requested, I went to desk as soon as I got my room assignment and asked for a change which was graciously granted (had asked for building 6 and was put in building 2. Was able to get a room in 6 with no problem. Not sure why they didn't put me there to begin with!)
Usually get same area requested at AS Movies. The one time I didn't get request, I was upgraded from standard to preferred. I had requested Mighty Ducks and was put in 101 Dalmatians. Was still pretty close to area I had requested, so was very happy!
One floor down but same general area requested at Coronado Gran Destino Tower.
Booked standard CSR once and requested Casitas 4, was upgraded to preferred, Casitas 1. That was a great location and I loved it!
At AKL, when I book standard, I always request partial savanna view and have always gotten it.
Have never gotten anything close to my requests at YC and they are always very reluctant to move me to a different room even though I don't go in the room once I see the location. I have 2 reservations coming up here soon, so will see if my luck changes!