If you are asking about pre-k, and not the kindy, then I have experience with YC as my son went there for his "2-yr old class" . I have to say although schools fees are a bit hefty, you have a good campus and 3 dedicated teachers (+ 1 helper/nanny for EACH class) to look after your kids - thats a lot of attention there for each kid. Teachers - I find that each teacher has a different style, that said, it has an impact which I thnk is positive because the kids get teachers who are a bit stricter, some are more relaxed, some more authoratative etc...I think my kid generally had fun there, and I think they do a good job with the separation process - I think both my son adn I felt comfortable with how the children separates and they are very quickly on their feet re going to school alone. we had about 2-3 field trips in pre-K, and YC have their own little farm where kids go to on field trips ( and we went alone on a weekend which is also fun) . kids get good amounts of outdoor time with the sand box and pools, and I think all in all they had good fun.
if we are just talking about the pre-k level, I think most parents I know of tend to think positively of it.