Sihoo Doro C300 Ergonomic Office Chair vs Autonomous ErgoChair Ultra 2

Buy the Doro C300 if you want a chair that fits a wide range of bodies and lets you dial in support: 4D armrests, an adjustable headrest, adaptive lumbar and a 130° recline. Buy the Ergo Chair Ultra 2 if you sit for very long stretches and prefer support that comes from a flexing frame rather than knobs, plus a lifetime warranty and tool-free assembly. The C300 has the deeper review record and more adjustments; the Ultra 2 has the sturdier long-term frame story and simpler setup. Owners of both praise the breathable mesh and solid build, though C300 owners report occasional seam failures around the one-year mark, handled under warranty.

• Choose the Doro C300 if you want a headrest, 4D armrests and a wide adjustment range for a body between roughly 150 and 180 cm.
• Choose the Ergo Chair Ultra 2 if you sit 10 to 12 hours a day and want a flex-frame back, a lifetime warranty and assembly in under five minutes.