Personally I felt that my lifestyle didn't suit halls at uni, I have been engaged since I was 17 and I felt there were too many rules and restrictions in halls for my lifestyle, I did however feel like I needed the freedom of living alone, and renting out an apartment with two of my best friends in Belfast was perfect! You're in the middle of it all living in the student part of town, there's always something to do! Some UV party, or pub crawl, or gig, or poetry reading in Botanic Gardens!
I think choosing who you're going to live with is super important! I lived with 6 fellas once (5 of which were strangers before we moved in) and being the only girl in the house drove me a little mad! It would have helped if they had of been fairly tidy...that's another point, living with people who have never been away from home, some people just can't cope without their Mum! Sharing rent with more people may be cheaper, but more people = more mess!
One thing I do recommend for finding student accommodation outside of halls, is to start early! Don't leave it until August/September to start looking for a place, by that time all the good places are gone, and you'll end up living in some tiny moldy, damp ridden flat! (Former house mates previous experience) start looking as soon as you know what Uni you're going too! And in second year onwards, don't leave it until you're moving out to start looking, start as early as say April, so there's no last minute mad rush! Remember where ever you find you'll have to live there for at least the next year, so find somewhere you like :)
Also some helpful hints, places near amenities go quickly (ie beside the pub, library, train/bus station). Because you're a student, landlords and estate agents will look at you as a 'student', don't let them walk all over you! Take photos of everything before you move into a new place, any cracks/damage/mold/etc that's the sort of stuff you'll lose your deposit over!
And of course have fun! You'll only do all this stuff for the next 3-4 years, after that it's into the 'real world'! ;)