I've seen the recommendations get better then worse then better again as they tweaked the algorithms. Right now it's better than it's ever been. Again, for me.
One complaint: I like to upload interesting clips from this or that. I got my first copy right strike on a clip of Russel Brand talking to Terry Gross of NPR about life on heroin because I thought it was helpful for people. YouTube told me I could only get 3 strikes before they disabled my account, which I assume they mean they will disable my GMail. I can't have that so I don't upload interesting clips anymore. In fact, I don't upload anything since I don't want to lose my GMail. So the complaint is why didn't YouTube tell me when I uploaded it that I couldn't? I'd be ok with that.
So I give Ms Wojcicki a people choice grade of B+ overall