Once we stayed at PP and got the view upgrade for free, very high up floor too. That view is really spectacular and one night after the park closed, there was a private party and it was fun to be able to watch and guess who it was-lol.
I know that you only asked about GC and PP but, in March we paid for a resort view regular room at the DH and got upgraded to a suite!! Only problem with that is we are all spoiled now and felt so so cramped in the regular room last week-lol. For that trip, we paid for a view and got the DTD 7th floor view nice view but so noisy not sure if we really liked it or not.