Many years ago we got an upgrade from POR to WL, but we knew ahead of time. Someone called us and asked if we were interested. We actually wavered, as we had wanted POR, but decided we couldn't turn down an upgrade and were so glad we did. I love both resorts, but there's just something about WL that I love, and I love balconies that you can't get at the moderates. This was way before online check-in.
We've gotten an upgrade at POR from SV to water view (or river view, whichever they call it) a couple of times out of many trips. They never say anything, we just see it when we get to the room. Once was a great corner room with a view of the river and the water wheel/main building. I never do online check in.
Out of 25 or so trips, that's it. We got married at the WL and didn't get an upgrade for the stay (again, not that I would ever expect one at Disney, but if there was ever a time to think about one that might be it). I guess I don't think about it much, I would love an upgrade but book the room we want. The only time it crossed my mind was when we stayed at the Poly GV CL. I had it in the back of my mind that we could get a LV or TPV upgrade, but no dice.
Just wishful thinking, and we had a great GV room. But jokes on us, as we booked LV CL this year. See, they get our money for the better view without even enticing us with a free upgrade first
Seriously, we would have booked GV again but couldn't get it with the RO discount.