Hounddawg,
I know the Autotrickler uses magnetic force restoration. The maker had a table at the last NRA Annual Meeting gun show and had the internal parts from one out on their table to help them explain it. I don't know about the RCBS, but suspect it is the same. Everyone gets fed up with last decimal place drift from strain gauge and capacity load cell drift and the magnetic force restoration method cuts that way down. I have a small, 60-gram auto-calibrating analytical balance made by Torbal that uses that principle to read out to tenths of a milligram (0.00154 grains), and even those tenths drift very little. It is a way better mouse trap, for sure. But you have to pay for it.