Just keep in mind that Uber's not a great network in San Juan. When we arrived, we had to wait 5 minutes for an Uber, and the driver then cancelled on us. We had to wait 5 minutes more, and that was for a driver who was en route to make an airport drop off. We were unable to get an Uber on our way out of the airport; and we tried for a period of 20-30 minutes. When we finally checked out and asked for a cab, it took about 30 minutes to get a cab to us. The bellmen were saying that's not typical, but I didn't see cabs readily available on the property.
In terms of the cost, Uber is $30-$40 each way to/from the airport (the to rate was the rate our app was showing us, though there were no cars available). We paid a cab $65 plus tip for the ride from the hotel to the airport. I believe it included at least one toll on the ride to the airport.
These factored in our decision to eat at the hotel each night. We were there for only 3 nights, so it was easy call for us.