Like Neon_Duke, I too have experience in both Private and Public schools.
From Kindergarten, up until last year (8th grade) I attended Private Catholic Schools. For me personally, the experience was wonderful. Although I am not Catholic (I'm non-denominational basically. I've got Apostolic, Pentacostal and Baptist shooting at me from all sides of the family) I am Christian. It was a lot of fun, educational, challenging, and family friendly. But...there was set backs.
Because I was not Catholic, the tuition was a lot more expensive than what the Catholic students had to pay. Why? Since we did not belong to that church, or another Catholic church, my tuition was higher for the fact we had not "contributed" to the church offerings and such. For one thing, I thought this was kind of ridiculous. We already attend a church of our own, and paid our offerings to that one. Sheesh.
Diversity was an issue to. When I was younger and going to the Catholic schools I was a bit confused up until around 3rd grade. I didn't understand. All I knew about was Jesus, God, Mary, Angels, Heaven, Hell, Satan...you know, the Christian typicals. Denomination was never a factor in our family so to me, attending a Catholic school was a bit of an experience. But my biggest problem was how limited I was to participate in certain things. Again, because I was not Catholic, and raised in a Catholic family, I could not participate in a lot of what the students were doing. For instance, when 4th grade rolled around I wanted to be a Server just like the other kids. For all of you who do not know, a Sever is helpers basically. They'll get the Bible for the Priest, the bread and wine, cloths, etc. So to me this was real exciting. Then I found out I couldn' t because I wasn't Catholic. Ouch. So I'm bummed. Then there's school plays and musicals...the Catholic kids ALWAYS got the parts. And I loved acting too. I was just never given a chance.
Here's the big problem that just happened last year. It's the 2nd to last day of school, a Friday. Our 8th grade graduation is coming up. We're excited. Woohoo. We had been practicing for our Graduation Mass all week. My religion teacher picked me to do a reading. It was a great reading, too. From the book of Kings. It summarized everything I felt and wanted to tell everybody. I was going a good job, too. I had never done a reading, so getting picked was special for me. Well, that Friday, the Priest confronts my religion teacher and tells her I can't do the reading. Why? I'm sure you know why by now. I was infuriated with the Priest. All I could think was "Why?" With the exception of two years (6th and 7th grade I went to a different Catholic school thanks to this Priest and his religiously segregated ways) I had gone to this school from Kindergarten all the way up to the 8th grade. And after my family spent over $2,000 in tuition, this is how you pay us back?! Needless to say, it put me in tears big time. It made my religion teacher cry, too. On a side note she quit her teaching job there early this school year because of problems like that with the Priest.
I'll give my view on Public schools on another post so I don't give you all a headache.

But education wise, Private schools are great. Family friendly? They're appropriate and sometimes too strict. But they're good for you first schooling years. After Jr. High, I suggest a taste of the real world--High School. So you're better prepared for life that way.