Ok I don't really do YouTube either, save the embedded clip here and there :) So I wasn't aware of that. Videos as a content format don't really appeal to me anyway.
I did check one and I don't find it a huge difference. In particular I noticed that Google is much better at keeping state for follow-up questions. Something that bothers me with Siri.
But the other answers were pretty much the same. I won't change it for that :)
Privacy is a completely different subject and whatever we feel about these companies it is very hard to quantify.