Omega Speedmaster Calibre 321 Chronograph 39 7mmvsSeiko Prospex Speedtimer Mechanical Chronograph

Owners and reviewers widely praise the Omega Speedmaster Calibre 321 Chronograph 39.7mm for its historical fidelity to the 105.003, its superior finishing, and the tactile feel of its pushers and bracelet, with some considering it the ultimate Speedmaster. The movement's copper-plated finish and column-wheel chronograph mechanism are highlighted as distinguishing features. However, its high price, limited availability, and lack of hacking, anti-magnetism, and crown guards are noted drawbacks. Accuracy varies, with one owner reporting +20 seconds per day out of the box, while others cite better performance. On balance, owners and reviewers rate the Omega Speedmaster Calibre 321 Chronograph 39.7mm highly for its blend of vintage aesthetic, superb movement finishing, and comfortable wearability, justifying its premium price for enthusiasts.

The Seiko Prospex SPEEDTIMER Mechanical Chronograph is praised for its handsome, heritage-inspired design and clean, balanced dial layout, enhanced by an external tachymeter bezel. Reviewers note the adequate caliber 8R48 movement, which features a vertical clutch and column wheel with MEMS technology for durability and precision. The refined bracelet offers improved comfort, and the overall package is considered good value for a well-designed chronograph with an in-house movement. Points to consider include the 4:30 date window and a thickness of 14.6mm, while the 45-hour power reserve is an area for potential improvement. On balance, reviewers rate the Seiko Prospex SPEEDTIMER Mechanical Chronograph highly for its attractive design and solid chronograph functionality at its price point.