I've used an Ohaus 10.0.5 scale for over 35 years. About a year ago my wife bought me an RCBS Chargemaster combo and it's fantastic. I've checked them against each other and with check weights they're always right on the money. No matter what scale you use, get a set of check weights and use them.
I got 2 old Ohaus balance beam scales. One is 38 years old and the other is a youngster - about 29. I do check one against the other (or at least I used to) but I'm not sure why. They always agree with each other and my check weights.
I have an old balance beam and my friend has a rcbs electronic, we check them against each other and with the weights. I might add that I trust with the utmost of confidence my friend and his very cautious habits.