I thought I'd never use Siri. It just seemed stupid. Much of that opinion is based on the fact that voice recognition just hasn't worked for me in the past.
However, for the most part, it really works. So, it's nice when you're driving along to just be able to ask your phone to do something. And it does it. Correctly.
With that said, I personally don't use Siri a whole lot. The person that uses it in our household is my wife. I can't really say how many times in the past month that my wife has told me or did something completely out of character for her (for example, I made arrangements to have her car in for service and she changed the appointment time and day) and when I asked how she knew to do it (e.g., how did she even know the phone number) she just replies "I asked my phone."
She's had an HTC TP2 for 2+ years (and a Moto Q prior to that) and she had NOT ONCE used either of them to look up information like that - despite my constant prodding to do so. (I mention the other phones partially to point out that I'm not purely an Apple bigot.) Now she tells me perhaps once every other day how much she loves her iPhone.
This is because "it just works" for her. If she were getting errors all the time or results similar to the SeeMe vs. Siri video that's floating around these days, she'd certainly never use it.
I'm sure Android will have something that's "good enough" one of these days, but from what I've seen, there still isn't anything yet that truly gives Siri a run for its money.