ORIGINAL: Campgems
Right, and depending on the plane, it can go from good CG to dangerous tail heavy with a small shift in weight. A 3D plane is a good example, Short length and huge surfaces with a lot of throw. That last 1/4'' has to be done in steps or you might not bring it back.
Don
Good thing about the small shift threat, is for a small shift to cause dangerously tail heavy, the CG has to be aft (and close to dangerously aft) already. It'll be far enough aft already that anyone would have already known the sucker was close to dangerous.
Small shifts of CG won't suddenly wake a sleeping monster until the CG is already aft. Since most CG shifts come as a response to how a model is flying, when the monster is aroused it shouldn't be a surprise for the guys who're wanting more response to an already responsive airplane, and shifting it aft a little to see if there was more response to be had.