I did my original groundschool at a different FTO but decided to go to Oxford for a brush up for my 3 resits. They charged 200 quid per subject. It was worthwhile in terms of getting the notes (which are excellent) and there feedback questions. The instructors I encountered were very good. However, the CAA are introducing the additional question bank in sept so for those exams feedback will not be the way forward. Whether Oxford did the trick for me, I'll only find out when the white envelope is (eventually) delivered from the CAA!!
Heard to many negative stories about their flight training to do my flying there though. Something else for me to think about.....
RM