What is the benefit of balanced xlr cables

I just bought a marantz av7005 that has balanced outputs for xlr cables and I have a b&k st 125.7 s2 to hook it to also have a older Cambridge audio cd6 that has balanced connections on it.what are my befits to switching to these cables over my rca stuff.What is a good brand without breaking the bank,I've used blue jean cable,kimber kable,and synergestic THX