I cannot disagree with Smooth Airperator and Piltdown Man.
I did the CTC ones a couple of years ago and was one of the 3 out of 15 who 'passed'. Failures included people who had passed the BA equivalent and were in their holding pool, together with others who boasted about having practised the tests in advance.
I found it pretty good fun to be honest, albeit stresful. And I'm an old boy! It certainly gets your heartrate up! A bit like total deathmatch in Black Ops.