Capetown - Used Uber X for a couple of short hops around the city and from DeWaterkant area to the airport and had late model economy sedans for all trips. Slightly cheaper than taxis. All showed up within a couple of minutes. Drivers were a little more chatty than I'm used to, but all in all great service
Madrid - I think I was the last one to use Uber in Spain! At the end of the year I was going from Chueca to the airport and got a late model sedan, driver was excellent and was MUCH cheaper than the cost of an official taxi. A few days after the new year, when I came back to Madrid Uber was gone.