I have been using the RCBS for a couple of years now and really like it. Occasionally you will need to run the "calibration" cycle on it to keep accurate, but it is not necessary each time you use it. I have two "test" bullets, one that weighs exactly 190 grains and another that weighs 300 as weighed on several scales. Each time I turn on the unit I drop the 190, then the 300 in the pan. If they are not right on I will run the calibration procedure.
I typically seat a bullet while the unit is dispensing the next charge, by the time I have a bullet seated the charge is ready, saves a lot of time for me.