I went suited and it was quite uncomfortable as I got more stressed with the tests.
Best go for something tidy and neutral (ie not your most flamboyant clubbing gear)
A couple of lads turned up for the tests at the same time straight from work which was on a building site. Dont think it matters what your wearing for the tests (mind you Ive never seen another thing of the lads in torn jeans and hard hats
)