About these personality tests:
Something just sprung to my mind and I thought I would let y'all know.
When I was working for Thomas Cook (as crew), we were all sat down in a classroom with a pilot who spoke to use about CRM.
One part of his day involved giving us all an answer sheet, reading a set of questions and four possible answers. We picked the answer most relevent to us (similar to the NATS quiz).
By the end of the lengthy process, he gave us a rundown of what marks we could add/deduct with regards to answering ABCD for each question. By the end of it, our personality was summed up by 2 numbers (which he used as an (x,y) co-ordinate on a chart he drew up)
Basically, myself and one other guy called Trev were only doing crew as a "foot in" to the aviation industry. We weren't particuarly keen on making a career out of it, although we enjoyed it nonetheless.
However, on the chart, all bar three of the crew in the room had co-ordinates placed above a threshhold drawn on the graph, and three came below it. Myself, Trev, and one female crewmember.
The pilot described how this line he had drawn generally seperated the warm/fuzzy crew brains from the cold/decisive brains of the flight deck :P
It was a bit of fun, but I am sure that this test is just one example of how even a relatively quick personality tests can bring forward some good results.