As far as the quality, they are all solid carbide, so they stay sharp for a long time, but they are brittle compared to HSS. I have never done machining until I got my SO3, and I was told about drillman1 and have been buying mainly from “him” (since I have no idea who it actually is running the store) but the bits I have purchased:
Have all been just fine. I don’t cut metal, and most of the wood I cut is exotic hardwoods (purpleheart, katalox, wenge, pau ferro, chechen, chakte viga, zebrawood, leopardwood) as well as cherry, and laminated bamboo. The bits last a long time, but sometimes I forget to reduce the cutting depth of the smaller bits and break them off when I try to make a 0.04" deep cut with a 0.0120" bit. Let me tell you, it does not work well at all.
Overall, I like the bits. They last long enough I think I am getting my moneys worth out of them, but if I break them due to “operator head space and timing issues” I don’t feel bad, because it was only like $4.00.
If you want to drill a lot of holes (like for a cribbage board for instance), the solid carbide drills are also a good deal. I can drill ~2,000 holes before the bit gives out. I use the 0.1250" and 0.0781" drill bits mainly for my cribbage boards.