Both are world class universities. There may be a rumour/idea/feeling that Cambridge is better for some courses and vice versa but ultimately no employer will really think much of the difference.
They offer different courses which is relevant HSPS only at Cam, PPE only at Oxford. Natural Sciences vs individual science degrees. If that's the case of course the decision may be easier, but I will be applying for law. The courses are very similar, though Oxford has more of a focus on jurisprudence and Cambridge has more optional modules. But I can't really say that is too important to me right now.
As cities they're honestly very similar for me, obviously Oxford is slightly bigger and more lively, in my opinion Cambridge is slightly prettier, but they are all negligible differences. I enjoyed both visits immensely.
My parents would quite honestly kill for me to go Oxford, it's literally the whole reason they immigrated to this country. But they've since suggested they would also accept Cambridge. Oxford is more well known in our home country, but internationally Cambridge is viewed just as well if not better. So that parental pressure for specifically Oxford is off now.
I have medium GCSEs, but I don't want that to be a reason to apply for Oxford over Cambridge, my predictions are good, my personal statement and reference should be good. There's the matter of the LNAT vs CLT, but I haven't sat either so I can't say which I'd rather do.
At this point is it not just a coin flip really? How do you make the decision, and how would you justify choosing that one to very strict parents? They want to know exactly why I'm choosing whatever I choose.