Shugs, this is something where statistics and 'odds' cannot represent the situation. If you are unfortunate enough to be knocked back, you fail at something more tangible than the personality test (stage 1 tests, stage 3 interview etc), and you spend the year working on the areas you failed on, you stand a higher chance of being accepted.
We do not assess a candidate any differently if they're a re-applicant.
in that sense I agree with Avenarius, in that if you fail the personality test and nobody gives you feedback, how can you take steps to improve.
The danger with giving feedback about a failed personality test (i.e. you need to be more decisive), is that next year the candidate may well lie to appear more decisive.