I have a Lyman DPS III. I really like it. However,, the few quirks. As noted,, air currents can affect performance. I also don't use any of my electronic scale stuff around fluorescent lights. Apparently they too can cause deviations. I use LED lights.
Lastly,, the feature of how it slows down to trickle the last few grains can be a bit finicky with large grain powder. I did a slight modification to mine,, but at the moment, I can't recall what I did. It was to the powder feed tube I tinkered with Lyman sent me a spare to work with. That was years ago.
I really enjoy mine though. It gives me darn near perfect identical powder weights at a speed I can enjoy. Beats the heck out of throwing a charge, then weighing it.
Not cheap units,, but if you are really trying to be as uniform as possible,, and want to actually save time by not having to weigh each thrown charge individually,, worth the money.