Our most recent vacation was a "Universal" vacation with ONE DAY at the Magic Kingdom. At MK, we booked all 3 of our fast passes before 1pm, and then we were able to continue booking all day long, going from ride to ride, using my wife's phone. There was no planning involved. We got to ride all of the headliners and we never had to wait for anything at Disney the entire day. I guess we got lucky, but man I loved it.
At Universal, because we stayed at Cabana Bay we had to wait in a long line for everything and didn't get nearly as much done. We were so tired at Universal from waiting in those long lines. (Please note I am not a Disney fan, I'm a Universal guy...but I'm just stating my experience).
My family SPECIFICALLY enjoyed Magic Kingdom much more because of this and now they want us to take a "Disney" vacation next time. I had to break it to them that the rest of the Disney Parks don't have the same number of rides as MK and that we would need to wait until Star Wars and Avatar gets built.
As for Universal, I'll never stay onsite again without staying at one of the 3 fast pass hotels. Its just a shame that they cost so much. I wish there was a way for non onsite people to get access to a small number of fast passes at Universal without having to pay extra. (Yes, I understand the argument of how fast passes make the lines go up for everything, but I still like it myself because this "broken system" really works better for people like me who can't afford to stay in the fancy hotels).