I personally have not used Uber and can only relay second hand info from the Mrs.; who by the way is using it like a taxi service on a daily basis in Taipei for past two weeks. Couple of data points:

1. She calls from a post paid Taiwan number, hasn't and doesn't need to text. But that option is available to her.

2. After every trip, an email is sent to her with a confirmation of the charge, the routing of the trip. It includes a google like map, with detail breakdown of fee: basic fee, traffic/stop time, etc.

3. Everything is linked to a Chase Sapphire credit card -- so no cash exchanged. CC automatically sends email alert/update on every charge. Slightly OT, this auto alert is unbelievable -- I will have charged gas or purchase and before I even drive off or walk out of store, it pings the email already!

4. As far as pricing, she is amazed how competitive it is to local taxi. She is originally from Taipei, so knows the city and local taxi fees.

She uses a gmail account for above and filters are set up to automatically file/label under 'Uber service'....