for balance beam i have tried the new RCBS 500gr scale, Dillon eliminator and Redding, all new manufacture. I love the idea of a balance beam and frankly, in terms of fine accuracy, all of them move the needle with a single grain of extruded powder. However, none of them will go back to perfect zero consistently. maybe older balance scales will, i have many reviews stating they don't make them like they used to.
In terms of electronic scales, i have had the RCBS 750gr and the one attached to my charge master. They both work very well, but due to the .1 grain resolution, don't have the same accuracy "potential" as the balance, one grain of extruded powder does not register on the electronic. I have considered buying one of more high tech electronic scales. However, practicality has got in the way for now. I shoot at a max 325yrds and the type of accuracy i want does not equate to what i need. So for now, i will resist the temptation to spend more money on scales.
the other thing i will mention about the electronic scales, is that i have found they can be sensitive the static. For quite sometime i could never figure out why my electronic scales would drift by .5 of a grain right before my eyes, very frustrating. Then i realized i was wearing my microfibre hoodie or similar garment in the dead of winter. Once i grounded myself, the drift issue went away, but not before investing in a dillion eliminator beam scale and the chargemaster. Overall i ended up ahead, love the chargemaster.
Practically speaking i think each scale measures to the advertised .1 grain accuracy. So, i'd say up to personal choice. I find the electronic faster, easier and as accurate as i need, even though maybe not as accurate as i think i need.