To my mind, if the RCBS scale is a strain scale it can only be marginally better than the existing model, the CM 1500 or lite. The A&D scale and similar, are magnetic force restoration scales and as such not subject to drifting like the strain scale and have fast solid response time. The repeatability of a strain scale is simply not up to the level of a good magnetic force restoration (MFR) scale, by its very design.
If you held back on the Autotrickler setup that runs on a MFR scale hoping that a cheaper strain scale will be just as good, prepare to be disillusioned. It's not just the accuracy of the scale, it is also the response as you trickle powder.
An MFR scale generates a magnetic field that holds the platen as a certain point. When you add some weight on the platen, the scale (a balance, really) will use more power to keep the platen at the same point in the vertical axis. By measuring the difference in power used, the balance calculates the weight that is placed on it. You can tell that your scale is an MFR design easily since you can feel the power applied to the platen as soon as it's plugged in. Just carefully put your finger on the platen and you can feel it.
A strain scale is a lot cheaper to manufacture and it measures, as the name implies, the amount of strain placed by the load on the platen. The loadcell in the scale will convert the force of that load to a digital signal that is used to measure the weight. These scales are fine to weigh something that does not change or change quickly. Also, they drift over time, whereas an MFR does not.
The price difference between MFR and strain is substantial; that's just the way it is.