The K6 is what happens when a $95 grinder decides to embarrass the $200 competition: grind quality that rivals far pricier machines, 18-micron steps that handle espresso through French press, and metal construction that feels like it'll outlast your countertop. The adjustment ring can jam at extreme settings and need disassembly to reset, and light-roast espresso will give your forearm a workout unless you grab a drill attachment. If you want thick, syrupy body or grind ultra-light naturals daily, this isn't your grinder. But for pour-over devotees, travelers, or anyone tired of blade grinders turning beans into sawdust, the K6 delivers café-quality results without the café-quality price tag.
The C3 is a handsome, well-built hand grinder that makes good pour over coffee but has been quietly retired by the market. The grind dial can slip or free-spin at certain click positions, forcing you to recount from zero mid-session, and espresso grinding demands a full minute of hard cranking for a single shot. If you already own one and brew pour over, it'll keep working just fine. If you're shopping today, skip straight to Timemore's own S3 or the Kingrinder K6, both faster and more reliable at the same price or less.