The Withings ScanWatch 2 outperforms on battery (30 days per Withings specs) and health sensors including ECG (validated in CNET reviews), while the Garmin Vivomove Trend excels in design integration with fitness apps (per Notebookcheck). The ScanWatch 2 edges ahead for users prioritizing minimal maintenance, but the Vivomove Trend suits those wanting lighter daily wear. This is a close call on...