Digital scales are much faster, but dollar for dollar a beam scale will be much more accurate (up to a point).

My charge-master digital scale has a resolution of .1 grains, which means that it is typically rounding to the closest tenth to get my final weight. My beam scale however can show me if am less than a tenth off in either direction, which helps me be as accurate as possible. Normally this isn’t a big deal if I’m weighing relatively large charges (50-60 grains) of rifle powder, but if I’m weighing pistol charges that run from 2.9-3.3 grains, I like knowing with a little more certainty just how close I am to the correct charge. Beam scales also don’t rely on power/batteries, are less prone to drifting due to environmental factors (like if your cell phone goes off), and doesn’t require 30-40 minutes to warm up before it starts being consistent.

If I could only have one scale, it would be a good beam scale. If I could have to 2 scales, it would be an accurate electronic scale that I can verify with my beam scale.