In might be testament to the RAF's training, but my opinion differs... I find it difficult to guess who in the RAF was an Air Cadet and who wasn't. From my experiences, after a few weeks everyone in the RAF was at the same standard.
One of the differences would be that ex ATC cadets were generally keen on aircraft and flying... during my 40+ years both in the RAF and aircraft industry etc only a low percentage of employees had any real interest in aircraft and flying !
rgds LR