The first thing you will notice between the four channel Kadet Sr. and the three channel version is the increased wing diheadral of the three channel version. This greater diheadral increases role coupeling when the rudder is used to make up for the lack of ailerons. While you can add ailerons to this model it still will not handle the same unless you remove a good bit of the diheadral as well. In addition to this the greater diheadral makes cross wind landing more challenging. As for the decision of wether it is a wise move or not, only you know and maybey this information will give you a little more insight as what to expect from the plane.