- Improved safety. You know the name of your driver and your trip is logged. Many of my wife's friends like this aspect a _lot_.
- Cleaner. At least in Chicago, many cabs are a stinky filthy mess. In Uber, with the ratings, such cabs would be out of the rotation pretty quickly.
- No standing in the sleet.
- No fumbling with cash or the argument over "broken credit card reader". Cabbies in Chicago make less on credit cards, so on most of my non-Uber trips where I want to use credit, the driver and I basically come down to a lying competition about me not carrying cash (lie) versus his machine being broken (also a lie).
Uber Taxi charges a fixed 20% tip and $1 booking fee.
Sources:
Then again, I guess I'm not super rich.
There are other companies in the same general space as Uber ("hail a cab with your smartphone") that focus more on the lower end of the market.
You know how you have a budget for your car loan/repairs/title/gas/insurance/parking? I have one for Taxis/Public Transit, and it's a lot less than what I used to pay for my car.