Xlr's carry a quieter signal especially on long runs and sometimes its connection will have a higher gain than the RCA. It is usually not as advantages unless your whole system is connected this way, ie, music source component. It also really depends on the equipment being used. Some sound much better with xlr and some with rca - you need to try each before puttuing out more money for xlr. Some components are true balanced for XLR while others just have an XLR connection.
