Medellin - Since few taxi drivers knew where our hotel was (even after explaining in Spanish), we fell into the habit of taking a taxi from our hotel to our destination and Uber back to the hotel, since the driver could just use the GPS. We used UberBlack almost all of the time (with the exceptions of one solo trip I took without my wife and the trip from the hotel to the airport, since we were leaving at 4 am and UberX was the only option) and it was usually within one or two USD of what we'd have paid for a taxi. Roughly 50% of the UberBlack drivers spoke English, none of the UberX drivers spoke English, all had clean, comfortable cars.