I agree with potkettleblack. It certainly shows up after groundschool when the real flying starts - the dubious statements made by some students show a lack of basic understanding in many subjects.
On the whole, the quality of ground teaching at OAT is good and there are some great characters instructing there
In general the teaching goes beyond the bare minimum needed to pass the exams and if you pay attention and put in a bit of work yourself you'll gain a good understanding in all subjects.
V1R