I've taken cabs from the airport to my house in Redwood City that have charged me $65 before tip, hassled me about paying with credit card, had no idea where to go and
at the end often try to charge me double because I'm .5 miles past the 1x rate.
I took a Lyft last time that was some nice lady, who just asked me for the address and followed the directions on her phone instead of pestering me, dropped me off without hassling me for any payment and it was $35 before tip.
Similarly I took an Uber from the city to my house the other night and it cost $53, no tip expected.
Uber and Lyft are mostly priuses (priui?), without some big plastic shield and ads strewn everywhere, though I've been picked up in immaculate Mercedes before. With Uber, I can get an estimate of the cost before calling for the car, while in a cab the prices just ticks up and up (biggest downside to Lyft is the lack of estimate).
I'm not worried about getting my head beat in with a hammer, especially not more so than from your average cabby:
http://blog.sfgate.com/crime/2012/05/30/s-f-cabbie-attacks-fare-with-tire-iron/
Seriously, every single thing is better about using Lyft and Uber than a cab. Everything!