I enjoy most of the teachers I've encountered in the MATH degree, but there are definitely a few bad apples.
KSU tends to hire a lot of foreign teachers, whose first language is not English, so a lot of times, there's a language barrier there. It can be hard to commuicate.
There are many American professors that speak perfect Engilsh, but they can be quite challenging as well.
Even with the best of the best (and there are quie a few) Mathematics and Statistics are tough degrees in general, so be prepared to put in many hours of hard work.