There are a lot of long-term students who can plateau and be attending lessons (possibly at the same level) every day for weeks/months without much in terms of motivation.
In the summer there are big groups of teens who are often not particularly interested in spending their time in a classroom learning and can be hard work to manage. Groups can be up to 14-16 students which is quite a lot for this type of teaching (although comparable to other schools in the area).
There is not much in the way of career progression if that is what you're looking for.