I've only used Uber once, after I called in for a cab.and asked for a fixed price to the airport. I was given a ridiculous number and a "maybe" along with it. Let's not forget a crazy 1 hour wait because of "rush hour".
I installed UBER some time back and I told myself.. why the hell not? I opened the app, provided my destination and was given a number that was significantly lower than I was quoted elsewhere. Intrigued, I hailed the cab and I was inside of it within 15 minutes! I confirmed my fare with the driver and I sat back.
I was comfortable in a spacious sedan, the driver was polite and friendly. I got to the airport without any issues. Once there my rate was respected and I was very impressed with the entire experience.
Did I mention you can track the taxi? Amazing.
If I regularly used a taxi, I'd use UBER more, for that single experience where I saved money and time? 5 stars.
YMMV