I began studying PPE full time at OU in september. I was previously at manchester university studying history and international politics, but dropped out because, like you, I didn't really fit in with the people I lived with, and the whole experience was pretty horrible tbh! Sometimes its just not meant to be aye.
Mate, don't worry about where you got your degree from unless you went to oxbidge. What employers look for is the class of honours and the subject studied. PPE is a complex inter-disciplinary approach into decision making and analytical research methods, it is highly attractive to most employers, not to mention extremely interesting as well. I am only a month into the course and I can honestly say it is the best decision I have ever made. The standard of teaching and feedback rivals and in some cases beats the quality I was getting at my former redbrick and In some respects the course is harder then degrees at built universities, because their you only have to get 70% to get a first, at OU it is 80%!
What's so great as well is that you can complete you degree in three years (take 120 credits per year) like normal and squeeze in working part time to earn extra cash! The degrees also cost 1/3rd less, not to mention the fact you don't have to talk to people/see people and can avoid the social life! Did I mention the OU uses teachers from the london school of economics and university of london, and it has the highest satisfaction ratings from students then any other university in the world?
As for the question what do graduates do - all sorts of things - teaching, public service, law, finance, research. But its worth remembering a degree does not guarantee you a job - I know people who did maths at britstol uni and work as checkout operators in banks. I also know people who did media studies at manchester polytechnic (one of the lowest ranked uni's in the UK) and work at PR companies in london. What gets you a job interview is your c.v., what gets you the job is your confidence, skills, and personality - you cannot buy these no matter where you go.
As for studying at OU, ask any current or former students and they will sing the same old tune that I have... Good luck.