The workhorse that made hand grinding mainstream: fast, durable, and genuinely excellent at pour-over for half what the boutique grinders cost. The ceiling shows up when you grind fine for espresso (slow, laborious, not worth it) or when you've been brewing long enough to taste the clarity gap between this and a C40. Most daily multi-year reliability and zero regrets, but experienced coffee people treat it as the grinder you graduate from, not to. Buy it if you're starting out, need something compact for travel, or brew filter methods on a budget. Skip it if you're already chasing tasting notes or need a true espresso hand grinder.
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.