This is purely anecdotal but I thought I'd stick my oar in anyway
I went to a Catholic school as it was the nearest school to us and, at the time, it had a great reputation. We were brought up as Methodists (not a great start in life ) but that didn't seem to bother anyone - parents or school.
Apart from several of the teachers getting sacked for paedo-ing the kids, or battering them (corporal punishment being illegal), a few of the older pupils slept with some of the younger teachers; I learnt more than I ever needed to about sex (not from the teachers!), drugs, violence and breaking into cars. Truancy was rife although the school LIED about it on paper - they claimed they had a 0% truancy rating!!
The best education I got was actually from my poor, worn-out parents. And I've not done too badly
So the moral of this story is schools change, their standards fluctuate, you never *really* know who's educating your children and the most important lessons, values and standards they learn will be from watching you - their parents/guardians - and the time you spend with them.