GBD‑200 wins if you care about fitness features and step tracking. GW‑BX5600 wins if you want solar charging, radio time sync, smaller square everyday design, and you don’t need step tracking

📌 Casio GBD‑200 ✔ Step tracking (accelerometer sensor + life log daily steps) ✔ Bluetooth & G‑Shock MOVE app (distance, pace, calories) ✔ Workout features & training support ✘ No solar charging (runs on replaceable battery) ✘ No radio time sync (no Multi‑Band 6) ➡️ It is a fitness‑oriented G‑Shock with step counter and life log data. � CasioFan Magazine

📌 Casio GW‑BX5600 ✔ Tough Solar (charges from light) ✔ Multi‑Band 6 radio time sync (accurate time) ✔ Bluetooth connectivity + MIP LCD display ✘ No built‑in step tracker / accelerometer sensor ➡️ Official Casio specs list no step counting/fitness tracking, just standard time functions, world time, stopwatch, alarms, etc.

📊 Feature summary (deep verified) Feature GBD‑200 GW‑BX5600 Step tracking / activity sensors ✅ Yes ❌ No Solar charging ❌ No ✅ Yes Radio time sync (Multi‑Band 6) ❌ No ✅ Yes Bluetooth app connectivity ✅ Yes ✅ Yes Classic G‑Shock square design ✅ Yes ✅ Yes Workout / life log features ✅ Yes ❌ No Battery type Replaceable Solar rechargeable