What are the pros and cons of teaching multiple sessions of the same course? Teaching at least two courses is necessary in my institution.
Because of a very busy schedule and lack of time for doing my other academic duties for the next semester, I am thinking about teaching multiple sessions of the same course (in the same day) for the next semester. The course is the freshman calculus if that matters. The good thing is that the course has many TA's and they grade the exams. In each session (in a big amphi) about 300 students are enrolled.
I taught this course at least 6 or 7 times in the past (only one session) without problem.

I write this to ask what are the pros and cons of teaching multiple sessions of the same course?
I ask this question because I have never taught a same course in multiple sessions.
I found this link
http://www.chronicle.com/blogs/profhacker/teaching-multiple-sections-of-the-same-course/38472

But I would like to ask your opinion about this. Especially your personal experience would be helpful to me.  

Sometimes when I teach two courses with some similarities (e.g. some intersection between their topics), at times I get confused, I think I have covered some topics in one of them, but in fact I have not covered it. Fortunately I ask the students about that. But for an identical course I don't know what arrives. 

This is only one aspect of my question. Feel free to give your opinion about other pros and cons.
I've done this.  The big con is it can be incredibly boring, but maybe that's just me.  And agreed, what did I say to the one class and not the other?!  The big pro is it can help you refine your materials and teaching methods.  I've had two of the exact same classes taught in the exact same way produce very different results.  

Write some things down before you start.  If nothing else this becomes a checklist to get you through the semester.  Goes a long way to keep from getting confused about what you did or didn't cover.