[quote=Lucian]
Was it much different?
[/quote]

Not really. There were more students and it was much more diverse. Didn't have to wear a uniform anymore so I never understood why people complained about the dress code. Didn't have to take an hour out of each school day to attend mass, or observe religious holidays like Lent. No more religion class either. The students were poorer, because most Catholic schools are expensive to attend with the cost of uniforms and tuition. Teachers (and the staff/administration in general) paid less attention to the class, and students were subsequently more rowdy.

Basically what you'd expect the differences to be. I'm glad I had the experience of going there, I think it helped build me up to be a more mature and respectful person. That being said, I am now Atheist. Things don't really stick too well in a young mind and later on once I started public school, I started forming my own thoughts about all that, and eventually concluded that I was Atheist. 

Happy to answer any other questions you might have about it, if you care.