Went down for my stage one yesterday, the 7th.
Like people have stated before, quite shocking how many failed the initial test.
I went in at 11.15 with 26 other candidates, 15 of these failed to get past the first test. I'm not the best when it comes to revision as I lose motivation easily and watching tv or doing anything but revising always seems appealing. If anything I felt I had underprepared, but thats just me.
Like I say, the first test, "Motivational Paper", is the one variable you can control. If you're not willing to put in the effort or absorb the information then you're just gonna be wasting your own time! Its as straight-forward as you come the first test.
The psychometric tests are the point where you either have the capabilities to do it, or don't. This is what I'm waiting for the results of.
Oh and one more thing, when you get there, enjoy yourself! Have a laugh. So many people seemed scared to breath! Me and this other guy just had a good laugh and both made it to the end, being relaxed can only help.
Good luck!