I had a Gempro and was not impressed with it at all.
I could trickle up to a weight, then pick up and replace the pan a few times and get a different weight each time. I would also then replace the empty pan and find the zero was now off too.
I think the 0.02gn alleged precision offered by the readout is tempting, but in reality the scale is not precise enough to make use of it.
I now use Lee throwers and trickle up on accurised 505s with a Targetmaster for peace of mind, but I haven't actually noticed improved groups over using just the throwers.
It might be worth noting that David Tubb throws all his loads for 600 yards and under and seems to do OK.