HN09,
Just saw your question regarding the questionnaire, to be honest the opinion of the other candidate you mentioned sounds like rubbish to me. I say this for a number of reasons:
1. I answered the questionnaire honestly and certainly did not put "strongly agree" or "strongly disagree" to all, or even the majority of the questions... but I did get through to stage 2.
2. I think the OPs opinion, whilst initially seeming to have some merit, is in fact very simplistic. You can waste your life away trying to second guess what people are looking for on these kind of tests, but I'd be very suprised if it was something so simple as "we want people who show decisiveness". Answering all the questions "strongly" could also show a number of other things, for instance that you are very opinionated, which might suggest to NATS that actually you may not be a very easy person to work with (so you are decisive, but not prepared to be corrected if those decisions are wrong, for example).
3. NOT answering the questions honestly seems pointless to me anyway. The entire reason that NATS have such a comprehensive selection process is because they are looking for people who have certain aptitudes and character traits which they believe are important in an ATCO. Being an ATCO is not, from what I can ascertain, and easy job. NATS are looking for people they believe are the right kind of person to cope and perform well in that job. If you are not that kind of person then pretending to be (by lying on the personallity questionnaire, or in any other way) won't actually be very helpful, either to NATS or to you. Its worth noting that even after this selection process a considerable number of candidates fail either at college or OJT before validating. It costs NATS a lot of money and wastes you a lot of time if you only get so far before failing because you've misrepresented yourself during selection.