Just my humble opinion here, but it sounds to me like you're doing the right thing. You came in as a high handicapper, and are steadily bringing it down by consistently improving. Isn't the entire purpose of the handicap system to create balance and give everybody a reasonably equal footing? Sandbaggers are people that game the system and intentionally keep their handicap high by either playing off or by only registering bad scores into the handicap system. Unethical at best.