take solid state or statistical physics next

[SymmetryOfImperfection]

I'm a MS student in condensed matter/materials physics.

During my undergrad I was interested in materials science, so I took a class on solid state physics early; way too early for my own good. Expectedly I got an F. afterwards, due to having too many required classes and a schedule conflict I never got the chance to retake it. In other materials related classes like quantum mechanics, chemical thermodynamics and statistical physics I got A's.

My current school was so nice to me and accepted me for materials physics research despite the F in solid state physics. Right now though I have a professor in that's so hard its physically painful doing his homework. The problem is, he's also teaching the solid state physics class.

Next semester I have a full load of TAing along with the dreaded graduate electromagnetism class and a required electronics lab. I'm scared of taking solid state with the "hard" professor and having that class drag down my other 2 classes.

I got an A in undergrad statistical physics, and I'm confident that I'll get an A in the grad version. The professor is also a very nice guy who has a good reputation. Its a required class also while solid state is simply my "elective" (but for my purposes it might as well be required).

But if I do not take solid state immediately, the F will be a mark on my record when I apply for PhDs next year and it might put me at a severe disadvantage. Also, the solid state professor is going on sabbatical next year and there might be no other chance to take solid state physics before I graduate if no one else picks up the solid state course.