How hard is STPM?

First of all I don't want to see those "STPM is really hard..." "I know someone that choose STPM..." Or "STPM is one of the hardest exam in..." etc. I want to know your own personal experience and thought on it. Not your relatives experience, not your friends, not your parents.

I'm currently waiting for my SPM result and planning to go with form six stem class in case I can't go to matriculation. I've check the syllabus, looks like moderate difficulty in my opinion but I might be underestimating it so I want to know your experience especially from the stem class students.