Hmm, I spoke up for Uber at SF MTA meetings and made strong arguments for them here against the incumbent taxi monopooly when they were getting off the ground. Although I have never used the service, I believe it provided much-needed competition.
On the other hand, I'm disgusted by Uber's bullshit legal argument that drivers are only employed by Uber during the time they have a passenger in the back, as a tactic to avoid liability in the case of an UberX driver that hit and killed a 6 year old child in SF last New Year's Eve. If they're logged into your app and checking for fares, then it's little different from being available for despatch in the same manner as a legacy cab (see http://www.sfgate.com/bayarea/article/Uber-sued-over-girl-s-... for a summary).
Uber is trying to have its cake and eat it here. I'm not inclined to support them if they're going to build their business model around offloading externalities onto the public.