For me, for rifle, the dispenser/scale combo is the best approach by *far*. I weigh each rifle round, and pistol while working up loads, for the same reasons you do. These units *will* speed up the process if you overlap dispensing Load#2 while seating bullet over Load#1.
I use a Pact dispenser/scale. It is equally accurate/inaccurate with either ball or stick, though it does seem to like VN-140 which is "tiny stick". Some days, some powders, some loads . . . it just wants to throw 0.1gr higher than the target 80% of the time. In those cases, I simply lower the target by 0.1gr so that there are no overcharges.
Overcharges (infrequent) are thrown back. All undercharges are dealt with the same way . . . press the "Dispense" button and trickle more powder in until the scale reads the target weight. After a few of these trickles you get a feel for how to trickle and you quickly hit the target without going over.
My charges are as accurate as the scale is, ie, +/-0.1gr of the target. They have correlated well with beam scale readings.
Bottom line on the Pact is that it works well enough not to replace it, but not so well that I would buy another Pact if it broke. I'd probably try an RCBS because I *think* its a bit faster and there's room for improvement in scale flutter, settling, and hitting the target weight with the initial throw more frequently than 80%.
The Pact scale not only needs time to warm up, but the reading fluttered every time I moved the power cord. Fixed that by adding ferrite cores at each end of the scale AND the dispenser power cord. At some point I'll try feeding the units extremely clean power from an old PC power supply.
Since winter began the dispenser has a propensity to throw 0.1gr over target. While this isn't a real problem (adjust the target down 0.1gr), there's room for improvement
