Well, I called AT&T about their fiber, and after listening to a bunch of marketing spiel, I was told that I would get fiber, but with 10mbps!!! This is for what they are calling a gigabit connection. So, if fiber is coming from AT&T to Marin, it isn't coming in any great speed - and it isn't unlimited.
Right now I am getting 250mbps from Xfinity with a 1TB limit per month. After that, it is $10 per 50MB.
That sounds like a misunderstanding. Once you get Fiber, there is no more limitation as there is with old-fashioned DSL, and I'm pretty certain you would not be limited to 10mbps with it.
In comparison to Comcast, the AT&T Fiber will provide the same Up and Download speed, so 50Mbps/50Mbps, 100Mbps/100Mbps, 1Gbps/1Gbps, and it isn't as Comcast cable is. So vastly superior to what Comcast is deploying/offering at this point.