But Aeros also have excellent support staff, and it's own maintenance facility which keeps the aircraft flying. The staff are great too. You also only get 2 students per course and not the pre-requisite 3 which means you don't spend 2/3 of your time sat in the back of an aircraft. I used Aeros and I am now employed with a major UK player.
I'm not sure about the DME dropping out in Exeter, I am based there and I have never experienced it dropping out on me, so even if it has dropped out it is so rare it is not even worth mentioning.