Over-prepping for stage 1 may be counter-productive, for the aptitude tests at least. I'm pretty sure part of the aptitude testing looks at improvement/learning curve - if you've overprepared on similar (or identical) tests you might be very good at them but show no trend in improvement. Maths/verbal is obviously different and preparation helps a lot.
On the subject of the BA assessment as a whole - there is enough info out there, all relatively easy to access, about the format and even quite a bit of the detail. Combine this with a reasonable dose of the character traits BA want and a bit of luck (like with any assessment process) and you should do well. Yes, there's a bit of game playing (I see this more as proper preparation) but where isn't there? I didn't get in a few years ago - it was lack of proper prep (for the sim stage mostly) and a bit of bad luck. This time I prepped properly and got in. If writing a couple of essay answers to questions and doing a bit of research in preparation is too much effort, why should BA give you a job? I don't think BA is for everyone but after putting in a lot of thought I came to the conclusion that BA would be a good move for me...so prepared accordingly. There's no guarantees of course but you can very much weight the chances of success in your favour with the right homework.
I wasn't bitter last time when it didn't work out because (a) I could have prepared better and (b) it's BA's train set - they can recruit who they like and are obviously happy with the end results of selection or it would be changed.
In all honesty this thread could have no more contributions and be closed now - applicants would still have everything they needed to properly prepare and do well. It's all already here (and in other threads). It just involves sitting down with a beer or cuppa and putting the time in to read it rather than repeat the same questions - the assessment hasn't essentially changed in years.
Good luck!
