Laura Burgess Martin, Special needs parent; work in non-profit sector
This is a great question that I'm going to answer from two different personal experiences.
I attended a liberal arts women's college. (I attended coed public schools through elementary, middle, and high school.) Attending a women's college had never crossed my mind until I received a flyer in the mail from this college the summer before my senior year of high school. I decided to visit the school and it ended up being the only school I applied to. I wouldn't say that my college experience was any more or less rigorous than my friends who attended a coed institution. I would say that my college experience was more focused than my friends who attend a coed institution. No, we didn't spend every hour of the day studying but we had an understanding that we were in college for our education first. Yes, we knew how to have fun. Attending a women's college were some of the best four years of my life.
I once taught at a coed private school that made the decision to split all middle school academic classes into all boys/all girls. The students were extremely skeptical at first but after one week, they loved it. As a chorus teacher who had a co-teacher, my co-teacher and I made the decision to also split our chorus classes. As with their academic classes, the students were very skeptical at first. After one day, they did not want to have a coed class. My co-teacher and I were able to teach each group at their own pace. At the middle school age, the students seemed to have much more confidence being in a single gender class. The girls didn't feel intimidated by the boys and vice versa. We once brought up the idea of putting the class back into a coed class and the students were adamantly opposed so we kept them in single gender classes through middle school.
In college, I had a very healthy social life. I met some of my dearest friends in college. While teaching, the students were well adjusted socially. They were able to see the opposite sex during class changes and during lunch but seemed to be much more focused in classes because of single gender classes.