I live with my boyfriend. Prior to moving to England in September, I had never been to England before. I met my boyfriend at a heavy metal festival in Germany, and he lived near where I was going to Uni. I didn't want to live in halls, though I had originally been slated to do so. I moved in with him and his family (which was a really good choice, in my opinion).
I absolutely love living with my boyfriend. We're extremely close and when we go out on weekends we go out together -- not out of obligation, but out of choice. We are like a married couple, but we enjoy it. It depends on what you want.
You will have a more difficult time making friends at Uni. I didn't participate in week one activities -- and I don't regret it, either. I dislike partying, and I enjoy the independence of living off of campus (and saving at least £4,000 in the process). I have some pretty good friends in my modules and on my course, and we talk a lot. We socialise outside of Uni as well, and it doesn't matter that I live off of campus.
You need to think about what it means to live together. Sharing things -- he might be paying rent, but what are you going to contribute? Who is going to cook? Are you going to share responsibilities? What is your relationship like now?
My boyfriend and I are hoping to get our own flat by the end of this semester. He works full time for BT and I go to Uni during the week... this works out really well for us.
It all depends on what you think you can handle -- would you feel left out of Uni life if you didn't live on campus? Would you feel like it would be harder to study?
I'm doing better than most of my friends in my modules because I'm not on campus partying. Living off campus lets me focus and works well for me. I also like the luxury of having a private bathroom, access to a kitchen, a living room, a big bed, etc.
You're free to message me if you want to talk about this or anything.