Casio G-Shock GA-2100 (CasiOak) vs Seiko 5 Sports Field GMT SSK023

Buy the Casio G-Shock GA-2100 if you want a tough, slim, grab-and-go watch that shrugs off knocks, water and grime. Buy the Seiko SSK023 if you want a mechanical watch with a true GMT hand and a steel case that looks at home in an office. The Casio wins on durability, water resistance and features per gram; the Seiko wins on movement, materials and finish. Owners of the GA-2100 praise its slim case and legibility, while the Seiko's 4.9 rating reflects its stronger perceived quality.

• Choose the Casio G-Shock GA-2100 if you need a shock-resistant, 200 m water-resistant daily watch with alarms, timers and Bluetooth timekeeping, and you prefer a light resin case.
• Choose the Seiko SSK023 if you want an automatic mechanical watch with a 24-hour GMT hand, a stainless steel case and a dressier field-watch look.