I've used Uber a couple times. It's pricey ($49 for a $33 taxi trip) but fantastic for those who can afford it.
Uber is better than taxi's in many ways:
o Taxi will frequently not take a trip if it doesn't like where it's coming from ("Bad neighborhood") - Uber doesn't tell the driver where you are until they accept the trip.
o Taxi will ask where you are going, and decline the trip if they don't like how much they'll make. Uber driver asks you where you are going, after you are in the vehicle.
o Taxi will sometimes take a trip, while they already have one - resulting in 30-45 minutes extra delay - hard to do with Uber when you can see where they are traveling.
o Taxi on the peninsula is usually 30-45 minute wait. Uber is < 15 minutes on average
o Drivers in Taxi's can be somewhat "eccentric" on the peninsula (As in, some of them scare me, they are so crazy). Uber Drivers are professional, rated.
o Vehicles in Taxi's are pretty craptastic sometimes. I've had to have the driver open my door (god forbid we get in an accident) - ubers vehicles professional Sedans.
o Airport Drivers will sometimes try and scam you for a 50% surcharge when they are still "in zone". They even try and pull that on someone like me who flys in and out of SFO on a monthly basis - I can imagine how many just accept it. Uber charges are identified before you book your trip.
o Lots of taxis will not take credit cards, or (try to) charge you a 10% surcharge - some of them would even RETURN to SFO when they discover you don't have cash. Uber is 100% electronic. No cash/credit card required, just your Smart Phone.
I love the electronic receipts, rating on the driver, certainty about when the vehicle is arriving.
On the peninsula, you pay about a 50% premium (or more, depending on demand), which is represented in the much higher quality trip you get.
I think if Uber was prepared to stick with that "premium" market, then the commissions wouldn't have a problem with them. Their concern is that, much like AirBNB was a trojan horse to get into the Renting Apartments/compete with hotels market, Uber is going to start competing with regular taxis - and for someone who has paid > $1mm for a medallion (http://blogs.reuters.com/felix-salmon/2011/10/21/why-taxi-me...) they are going to demand some sort of recompense and/or action be taken.
My guess is that there will be a strong correlation between cost of medallions and the resistance to Uber in any particular market.
What I would love to see, is that TAXI services adopt the uber model of source blind/closest taxi gets the trip/rate your driver/GPS location of Taxi/electronic receipts. It would be good for the industry, good for the customers, and good for the reputable drivers/services.
The only ones who would lose out would be the crappy services, with poorly maintained vehicles, and lousy drivers .