The only real difference is the needle and the connections for the buddy box are different. go with the old style that comes with the avistar as there will be more cables available to fit it at the field. The diff is the new ones use a sqaure connector and the old ones use round. so if you get the new style radio you will need a connector that is square on one end and round on the other. the old style will need a cable that is round on both ends, there should be plenty of these at your field

Terry