@Cesar R M just used them from a resort and if I remember correctly it was about $15 one way
Uber from Old Key West to the Doubletree by Hilton at Universal Orlando, was mere 14.95 USD according to Uber's App.
The guy gave us way better treatment than a normal MEARS taxi, so I gave extra as tip.
And yes, the Uber cab had no issues getting inside the DVC resort and pick us up from the Hospitality House.
Note that you can see nearby Uber cabs in the map application.
Infact, there were like 50+ Ubers in the DisneyWorld zone before the closer one accepted the request.
Also, theres Uber of all sizes even if you order the basic UberX.
The guy who picked us up, had a Kia Minivan , which had plenty of space.
Another one had a very big Lincoln, and the smaller one was of a normal black car that looked similar to a Nissan Tida.
Also, Uber from the parking lot of Universal Studios to the Hilton was just 4.45 USD each way. (in case you miss the buses, as most of them end their service at 8:15pm flat)
You can see an estimate of your fare here:
http://uberestimate.com/ .
I tried it and sometimes it does not "latch" to the place you want to go. Doesn't recognize many disney hotels..thus doesnt give you a proper estimate. No idea why.