Nico you are at Oxbridge?! It doesn't sound like it, because while the odd A more or less won't make a difference, overall you are exceedingly, exceedingly* unlikely get in to any degree at Oxford or Cambridge without a string of top grades. Maybe in the past, not any more!
Also, IME of oxbridge admissions, the personal statements were a useful starting point for asking questions at interview, and some drew me in more than others. But on the whole, there was really very little to choose between them and they counted for zero in the metrics that did or didn't get you to interview.
The distinguishing factors between candidates, at least in the humanities, were entirely down to the submitted essay, the pre-test, and (once whittled down from there), the interview performance. Personally I have strong doubts how far interview is a good measure. It tells you the very top, and the very bottom. For the mass in the middle (all of whom, remember, have top grades, stellar submitted essays and excellent marks in the pre-test, as well as exceedingly glowing references), I think a lottery would be the fairest way...