Citizen Eco-Drive OnevsGrand Seiko SBGV239

The Citizen Eco-Drive One is widely celebrated for its groundbreaking thinness, with multiple sources confirming its status as the world's thinnest light-powered watch, measuring between 2.98mm and 3.5mm. Owners and reviewers alike praise its exceptional lightness, titanium construction, and good build quality that avoids feeling flimsy, noting its "wow factor" and superb finishing. The watch features a proprietary, ultra-thin Eco-Drive quartz movement and a synthetic sapphire dial, with some models offering up to 12 months of power reserve. However, its high price, ranging from $3,500 to $5,000, is a significant drawback for some, and its aesthetic is considered too plain or dated by a minority who prefer other Citizen models. The Citizen Eco-Drive One is also noted for lacking a seconds hand and having only splash-resistant water protection.

The Grand Seiko SBGV239 is widely praised for its superb timekeeping from the 9F Quartz movement and its excellent finishing, which exceeds expectations. Owners highlight the dial's ability to pop even in poor lighting and its deep blue color that can appear black. The watch's 40mm diameter is also frequently cited as a positive attribute for wearability. Overall, owners rate the Grand Seiko SBGV239 highly for its exceptional finishing and the precise timekeeping of its 9F Quartz movement.