I agree with the digital guys. I am a scale technician by trade. I see electronic (digital and analog) and beam scales everyday. I repair, sell, calibrate and certify these scales.
When electronic scales first came into vogue, I would say yeah, the beams were whipping their butts, but today the industry is going toward digital. The electronic signal has been interfaced with computers and has become digitized and there is no way a balance beam can, or will, read out to the millionth of a gram. That's .000001g! "Krikey", we have scales with Quartz loadcells! This is all "readability" or divisioin size though. The farther you break down that signal and require more intricacy of it is where the digital NTEP approved scales start to shine. Most NTEP scales/loadcells (legal for trade) are rated for 10,000 counts internally. The counts are determined by capacity / division = counts (10,000lbs / 1lb = 10,000cts, 5,000lb / 1lb = 5,000cts, 100lb / .01lb = 10,000cts). This has nothing to do with balance beams and is a determining factor when certifying/calibrating scales with electronic loadcells. If most electronic scales, whether NTEP approved or not, are pushed past 10,000cts the displayed weight tends to "drift". This has been somewhat overcome with digital loadcell technology. The digital equipment can now read out past 10,000cts consistently and accurately.
The source of any scale's accuracy is in the standards you use (i.e. certified calibration weights). If you use a 10lb certified weight versus a 10lb barbell weight, your scale is going to be more accurate. It is held to tighter tolerances than the barbell weight and your digital scale "see" the difference electrically.
Beam vs Digital, hum.....3 four-drawer Filing cabinet(s) vs 1 Laptop. Come on. JohnnyK.