OK Andy. Things have changed, but then presumably changed back again. I was the first ATCO to enter the "Ministry" who had not undertaken the standard Primary Course. This didn't go down too well at Heathrow - some people were mightily upset and I had to work hard to prove that I was up to scratch. Oh yes, I only have two O levels and I got in purely on my past ATC experience which was in a foreign country. I don't follow why HR currently will not recruit similarly qualified ATCOs?
In my relatively short career in ATC training, I have found that the majority of trainees who progress through the college training and the UTP without problems back at their unit at a fast pace, are the ones who have a real strong interest and love of aviation but with only a minimal education behind them but with enough common sense and determination to do well.
Those who seem to have have fallen into ATC because of their excellent degree results after many years studying some unrelated subject at university do not always do so well. That said, this is not always the case and I work with one ATCO who has a fairly good degree result and some ATCOs who do not even possess one single GCSE/GCE or O Level!