The problem with the Gemini 20, for me, is the 20 gram capacity. That's only 308 grains.
That's enough capacity for most operations being performed by most reloaders, but nowhere near enough for what some of us do.
I also don't like the 0.001 gram resolution. That's 0.15 grains, which, of course, gets rounded up to 0.2 gr. ...but that's just me being anal.
All very good points. I load for pistol primarily, using a Lee Auto-Powder Measure and only load for one rifle (34.2grains) so the issues you mention do not come up for me but they are certainly valid. I am perfectly comfortable holding my mid-level pistol charges to within a .1grain spread (such as the 3.9-4.0 grain charge of N320 I am throwing currently). The .02 decimel readout is handy for reference more than something I hold to. The above charge will usually be 3.92-3.98 but occasionally I will see a 3.90 or a 4.00. I mark the charge in my notes as 3.9-4.0, or sometimes as 3.95 in the case of a well centered charge like this one.