Yep, I went there. Don't know the result yet.
What happens is that you start out with a 1 hr+ medical check. Thereafter you need to go to another location approximately 2 km away for a 6 hours computertest. The computertests consist of a bunch of personalty questions (Over 500), and various tests to check your concentration, multi-tasking skills, logical thinking etc. All in all a very different kind of assessment. It was more like an assessment to start an integrated ATPL course, as there were no aviation questions.
After the computertests there is an interview with a psychologist which last about 30 min or so. He will only try and and get to know your personality by asking questions like what are your weak and strong skills, tell me about the episodes in your life that have made the biggest contribution to the person you are today? etc.
It's hard to prepare for those computertests. Before each test they show an example. Just be prepared that once the actual test starts it will go much faster than the example.
Hope it helps
Zakka