Beyond if the legends are all clean looking while being placed properly & all the caps fitting & sitting how they are supposed to. Looking at the underside & how clean or sloppy the double/tripleshot is, is a good indicator of quality. Is there any flashing present in any of the caps is another good indicator (flashing is when you see a line where the molten plastic came together. If the temp is too low it allows for the plastics to not blend together well), then how big & visible the sprue marks are is another indicator of quality I will use to judge the overall quality of any double/tripleshot keycaps. The same holds true for dyesubbed & UV printed caps, but I tend to be a little more forging with the printed legends compared to double/tripleshot legends.