Personally, I find keeping my 505 and 1010 (even my Lee cheapo) in good clean working order and it works just fine in the consistency department. I learned the hard way that powder leaves a residue that needs to be cleaned off after each use. I also clean the pivot point & dress the pivot blade with an extra fine stone twice a year.
I can see a noticeable difference if I don't clean off the pan. Depending on how many rounds I make it can be off 2 -3 10ths of a gr. by the time I'm done.
I keep homemade dust covers on my scales, too.

I have read about electronics not liking to be near fluorescents or magnetics. It makes them act funky.
My favorite feature with balance type scales is portability & no need for power.