Depends really, on the Mentor, and the youngster, in my experience, if you keep the Youngster, Apprentice or Lad or Lass with the same Mentor as long as possible, providing the Mentor is a good egg the student will turn out a good un, it's continual changes in their training regime that screws many an Apprentice up, trouble is there is so much pressure on Tradesmen of all disciplines to produce as much profit as possible, there seems to be very little attention paid to training for the future, too much emphasis on fast track BS, someone please bring back the old Apprentice route for building trades, electricians included, how many times do we hear of 24 30 year olds looking for Apprenticeships? on a loser to start with at that age because of the social economic pressure on them.
How many of you have heard of reasonably established Electrical contractors employing a Youngster straight from School, and as soon as they can connect a CU up with a degree of safety and competence, chuck them out on site to run it themselves, it happened to me, but I luckily saw the writing on the wall and got out for a long while to retake Quals, and take more notice of what was available to me, there are many past and present forum members who can attest to this method, one in particular, but he has sadly not posted for a long while, he has his reasons I'm sure, and he is one of the good ones.