Choosing a college is one of those issues that divides. Some people will tell you that wherever you end up you'll enjoy it, whilst others are fixated on a single destination. And, because there are all sorts of college level statistics for entry success rates, it can get quite confusing.
The reality is that all colleges are different, and you need to think about the experience you want at university.
Choosing a college that is central compared to one that is further out will have an impact on your living costs and your social life. It is also important to look at the financial support each college offers if this is likely to be important to you.
Additionally, college size will impact on the number of societies and events you can take part in, and there are all sorts of differences which are harder to quantify - some colleges are more fun than others, some are good at sport, some have a strong public school feel, some have nicer food and some have reputations for certain subjects.
The best advice I can give is to talk to students you know at Oxford for their views - they'll give you the side that isn't in the prospectuses!
The other issue is admissions. The reality is that if you are good enough to study PPE, you'll be given a place somewhere - as lots of candidates are asked to interview at other colleges. The one thing that is important to consider however is that certain colleges are more competitive than others, so if you apply to Balliol for instance, you might end up getting offered a place at another college, so you may wish to apply to somewhere that is less competitive, because it means that if you do get an offer, it is more likely to be at your preferred college.
