I won't trust any scale until it's proven repeatable. By that I mean that if I weigh a check weight 10 times, I get the same reading 10 times. I don't zero my scales to 0, I zero the scale to the charge weight I'm going to load, using the check weights. So if I'm loading 50.0 grs of 4350, I put a 50 gr check weight on the scale first to ensure its reading correctly. If the scale gets bumped at some point through the loading process, I check it again, and adjust it if necessary.
As to type i have both an electronic and beam scale, and in my opinion the beam scale is more accurate. When I'm loading with the electronic scale, I'll check the charges with the balance beam, when they don't agree, I correct the charges to the balance beam reading.
When it comes to brands, I'm most comfortable with Ohaus, and least comfortable with the Lee powder scale, the example I had was wildly non-repeatable.