Hi,
I sat the assesment at cranfield last week and passed. Its not too difficult as long as you put in the work beforehand. Make sure you are completely familiar with the questions and subject matter in the physics and maths test questions on the cabair website and maybe try buying the software on pilapt-prep.co.uk.
Its debatable if this software will help you get a better score but i felt that by familiarising myself with the test beforehand i was a bit calmer and focused when being presented with it on the day.
hope this helps, any Qs feel free to PM me!