RE: rudder on a 1/2a worth the weight?
IMHO I don't think they are worth it....unless you are wanting to do some more precise aerobatics....but just for sport flying I don't think so....Dave's 1/2a Sureshark doesn't have a rudder and it flys great....he did add a rudder to his .15 size SS with the purpose of more aerobatics, but the weight penalty isn't nearly as bad on that size plane...
-Bill