I would say that for me, leaving home to go to uni made my relationship with my family better. You're lucky to have such a good relationship with them to start with.
HOWEVER, a word of caution - I would advise you and your parents not to visit too often as it may prevent you getting fully involved with your life at uni. If you're constantly keeping your eye on when you're going home next or whatever then it may detract from your experiences at uni. I think most people here, unless they live really close to uni, tend to go home just once a term (if at all) and I think this is about right. I communicate with my mum and dad in loads of different ways - phone, email, MSN, letters...you don't need to keep going home and keep having them visit you to maintain your relationship with them. Plus, think of it this way, most of the people around you will not be going home half the time and having their parents hanging around for the other half!! Are you an only child by any chance?
It is a big step to leave home even if you're coming back, and it's a transition that is bound to be a little bit difficult and unsettling. It's important to remember though that all your life your relationship with your parents changes, and leaving home, whether for uni or otherwise, is part of that transition.