Well, like I mentioned before, I teach high school. I also teach subjects, history and literature.
I definitely prefer 40 minute periods. I can handle 80-90 minute double periods with a break in between, because then I just do 40 minutes lecture 40 minutes practice, like you mentioned CP, and for certain groups that might even be optimal, but for my current students 40 minutes is pretty much the limit.
BUT -- how many times a week do you see your students? That makes a difference too. If you see them only once a week, 90 minutes or even longer makes a lot more sense than 90 minutes every single day. When I was in high school we had every class every day, and my typical high school classes that I teach now also are held daily. Occasionally there are times, mostly when I'm teaching history, when I wish I had time for a lecture and an activity in the same lesson, but doing a lecture today and an activity tomorrow isn't really a whole lot different and is less taxing for the students anyhow.