I have only been to all girl school too :)

I have been in a single school and I have been in a coed school. Maybe I do not have knowledge since I always end up between the outcast and average people group... It actually entirely depends on your friends and the type of people in ur school and also which type of country you are in coz the subjects they teach can vary. In my school, if drama and rumors spread.... it would die at most in a week and in the shortest time two days. It also depends on the type of class you get, classmates, school experience and etc. School should be fun yet learning. Boys may distract you once in a while but let it be just an infactuation and not a crush. I do not definitely do not believe in love at first sight especially coz 1) I'm too busy with studies and KPOP 2) Ain't nobody got time for a dramatic roller coaster life 3) based on my first and last love experience, heck no. These are my reasons for dating in school but back to the topic... Being in a coed school actually allows you to see yourself to learn and how to cope with people of the opposite gender. Because I have rarely been around boys since my 12 years on earth... It became a good opportunity to see the different perspectives on how boys think and sometimes, they can give you advice on maybe love, thinking wise and how each thought can be different yet similar in a way. At the same time, you get to meet new friends but do remember... be with the right group of friends

I have only been in co-ed schools and here is my take.

Grades wise, single- schools may be better off, but not by a huge extent (or at least not so for the top schools, and in my knowledge most single- schools tend to be one of the top schools so yeah). In my country, probably 4 out of the top 5 high schools are private, single- schools, and the remaining one is a public co-ed school (my old school =w=). My school tends to be 4th or 5th most years. I guess you can say that single- schools do perform better, maybe because they don't get distracted with dating and crushes etc (but then again my friend who's from a girls school says lesbians are pretty common there so IDK HAHAHA).

But I feel like co-ed school tends to be more holistic cos we grew up with opposite- classmates so we know how they're like and how to be like around them, how to be friends etc. And it also depends on your personality I guess. Some girls feel more comfortable hanging with guys ("girls are so sensitive and it's so stressful to hang around them"), some girls prefer an all-girls clique. I generally would say I prefer being co-ed, since guys are hilarious to be around and they make good bros.

not 100% percent sure since i've only been in co-ed schools... Grades wise I think it does matter (because dating and having crushes can be distracting), but to a small extent. In my country the top schools (private) are all single- schools. My school is the highest performing public school (I think it's 4th or 5th in the country, the top 3 are all private schools) and we're a co-ed school. I think it really depends on what kind of stuff you're looking for in your education. Do you want lots of love-love stories going on? Do you prefer hanging out with guys rather than girls (I have friends who are genuinely more comfortable with guys since they say girls tend to be very sensitive so its stressful to hang around them)?

I have only been in mixed schools and if you're as straight as a soldier and get crushes easily, YOU'D BE DOOMED. Tho sometimes it motivates you to go to school. If you're as straight as a cup of ramen, it wouldn't effect.

I personally just love being in school with boys since it's so funny when they think you can't hear but the fact is that teenage boys cannot whisper :'DDD God they have good stories

I only went to a co-ed school but I really don't think it's that different in terms of grades? I mean, grades usually depend on other factors such as the size of the class, the teacher etc. It doesn't really depend on the gender of the students in my opinion. (And no, I really don't think a crush necessarily ruins your grades either so...) I do think being co-ed makes it easy to socialize, though, and especially in regards to equality between the genders because your former biases will be countered to some degree and you're usually forced to interact with the other gender. I think that's a good thing.
Other than that - more things probably determine whether or not the school is good.

As for someone who has gone into both, I think being in an all girls / boys could make everyone feel at ease but it's not so different aside from the fact that both guys and girls try to be a little better because there's other people in the class. all boys / girls class seems to be a little easier to get friends though. I don't think there's much change aside from both.