I've been using uber for about 3 months now. It is fantastic.
If anyone wants to inbox me their cell # or email address, i can send you a promition code for $30 worth of free rides.
I travel a bunch for work and have used it in about every city too. 90% of the time you get a nice 1 or 2 year old car, in Seattle this week I kept getting a Pyrius.
A cab ride from my house, 1-10 and Shepherd to Minute Main park would run me $20 after tip, uber is $12. Uber is always 20-40% cheaper than a cab. No tip, no arguing with the driver over using a credit card or getting him to break a 20, etc...
I can't recommend uber enough. I haven't driven my truck to go out on the weekend in about 2 months. Uber takes less than 5 minutes to pick me up and have never waited more than 15 minutes.