IME the elevator is reasonably functional on a G103 Twin 2 Acro but it
could certainly use a better rudder.

Does it have the Z tape installed in front of the control surfaces as per
the Grob/Lindner optional service letter SL-12? If not, you might find
the effectiveness will be enhanced if you do install it. It works
wonders for the Twin Astir rudder... It is certainly easy and cheap
enough to try, and it is factory approved as well.....

RO