I loved my girls' school. Things I noticed from school/university days are that the girls from co-ed schools who were good at science tended to go on to study medicine, dentistry or vetinary science, while the ones from single-sex schools wete more likely to study pure sciences or engineering.
And as well as not dealing with harassment, in a single-sex schools the girls didn't experience chivalry. They carried their own heavy furniture, put out their own spiders and climbed their own ladders. They were the backstage crew for the school play, and played the drums and bass in the bands the girls formed.
The best thing for me about going to a single sex school was that for most of my teens, I didn't really think of myself as being a girl; I was a normal default human being. I didn't make adjustments to my behaviour around boys because it didn't occur to me that I could or should.
Within two years of leaving school, I found myself letting men carry heavy things for me, censoring my topics of conversation if men were around and doing all sorts of things which are now so automatic I'm not even aware of them but which happen because I no longer treat men and women the same.
Having said all that, my local catchment school is an excellent comprehensive which I am very glad that both my DC can attend. I have a boy and a girl who would miss each other in different schools.