IIRC the standard experimental result is that atheists who were raised religious have substantially above-average knowledge of their former religions.

As a Grade 11 student currently attending a catholic school (and having attended christian schools all my life) I would have to vouch for the accuracy of the statement; thanks to CCS I've learned a tremendous amount about Christianity although in my case there was a lot less Homosexuality is bad then is probably the norm and more focus on the positive moral aspects...

I currently attend Bishop Carroll HS and even though it is a catholic school I have no desire to change schools because of the alternate religious courses they offer and because it's generally a great school. From my experiences there are a ton of non-religious students as well as several more unusual religions represented. I personally would recommend the school for any HS students in Calgary wishing to have a non-standard HS experience.