I don't know whether this is a real difference or not, but Lyft "feels" like a much nicer company than Uber. I'm not thrilled about Lyft's rampant hipster-branding, but Uber seems like a company run by pricks.
Maybe it's just because they're the underdog, but I'm really rooting for Lyft.
Maybe it's just because they're the underdog, but I'm really rooting for Lyft.