In this case, I think you only like the middle school experience UNLESS you spend some physical days on campus with your cooperating teacher AND students. Working with only your cooperating teacher is sort of like having a great mentor - but it's not "real life" experience with students.
I think you could list your HS cooperating teacher as someone on your resume IF you engage in frequent pedagogical discussions. I wouldn't list your HS cooperating teacher as a reference if you only engage through e-mail.
As a college student - what are you doing with your time now? As we are in April, have you begun to apply for jobs yet?