RE: G4 Real Flight is great!
I have to agree with thevirginian. In fact it is one of the things I like about G4 is that it has coupling.
If you want it out i would recommend flying with your regular transmitter and using the programing of the transmitter to "mix" it out. Especially since when you mix it out it is never really gone anyway. (depending on the airplane if you mix it to be pure yaw in knife edge it will have some roll or pitch in level flight and vice versa.)
BTW I think I have one of the oldest computers that is running G4. It is a 2.0 G processor and I had to upgrade the video card to a 6200, but it runs great.
If it didn't my back up plan was to move it to a iMac, but I am avoiding putting anything microsoft on them mac . . .