A couple of considerations and thoughts ~ Round bales keep/shed moisture better then square bales when stored outside. They would both feed about the same and grind/mix same. Round balers are considerable less expensive then sq balers. Inside storage for sq bales are a must if in a climate that recieves moisture - I could never keep sq bales outside uncovered, where as with round bales and net wrap there is very little moisture intrusion into the bale. Just my quick thoughts ~