On principle, I won't use Uber because (some of) their executives are frat boy d-bag types. At some point within the past 15 years, that became acceptable here in Silicon Valley business culture. Besides that, many other people have complained about their business practices, which include flouting regulatory requirements, ignoring local governments and trying to price Lyft out of business (the side effect of low rates is that drivers become low-paid).
I do use Lyft, and their CFO (?) claims they've raised enough money to sustain heavy losses. That isn't exactly a viable business model, but it's been said they care more about their drivers than Uber does.
If I had to choose between Uber and cabs, I'd... hitchhike? (I'd probably pick Uber because I'm frugal, but it's a close call.)