Overall customers report the iO-series electric toothbrush handles plus compatible small round brush heads provide dentist‑level cleaning with quiet operation, a reliable battery for many users, and useful features like a pressure sensor, multiple cleaning modes, and an included travel case. However, a notable minority experience charging or motor failures, premature stoppage, and manufacturing or longevity issues; some users also raised hygiene (mould) concerns and app/connectivity or charger compatibility problems. Delivery, packaging and customer‑service interactions are mixed, with both successful replacements/refunds and reports of delays or lost shipments.