We had a horrible experience at one near us. I visited 2 near us and one that was pretty far away and unfortunately got the best vibes from the one that was just too far (I was worried about driving for hours in bad weather). The one near us looked nice and the director and teacher seemed fine.
Well, after the first day (a half-day) the director said to me, "We can't provide your son one-on-one attention". She said this after the FIRST DAY a 4 month old was without his momma. Definitely a red flag and I considered quitting work (which I should have), but I teach and I couldn't leave my boss hanging with no one to start. I was really hoping the teacher would be better -- but she wasn't she said something the second week about how he always wanted to be near someone. SO? That's what I would expect. He was definitely loud compared to all of the other children, but eventhough he is more "passionate", the other children were uncommonly quiet. He kept getting reports about crying all day -- one even when I stopped by twice and he was playing. I worry a little still that they gave him a vibe, because of there attitude toward him.
After 3 weeks we found a great room at the Y where they .... expected him to need time to adjust, put him on the couch with him when they fed other kids, and just kept him around them all the time.
I still cry thinking about him there. It was only 3 days a week, but it was such a bad experience. (And I did quit my job in December.
Icky -- but I think it varies from center to center. I felt very comfy with the one center. They seemed right on target.