As a general rule, the further forward the CG is, the more stable the plane. The further back the CG is, the more responsive/maneuverable the plane.
Go too far in either direction and the plane becomes unflyable. There's an old saying that a plane with the CG too far forward flies poorly, but a plane with the CG too far back flies only once.
Start with the CG near the forward-most position recommended. Then, if you want, you can experiment with pushing it farther backwards to find the sweet spot for you, personally.