So do I, and I have performed a manual reset quite a few times and no data is destroyed, although the MPW needs to be setup again as if it were out of box/new.
From user manual:
You can perform a system-only reset of your drive two ways: manually and on the dashboard’s Admin page. When the drive resets, your data remains but settings such as your password return to default values.You can perform a system and disk reset on the Admin page.
Manually Resetting the Drive
For a system only reset, the battery has to have at least a 25% charge.
1. With the power ON, hold down the Power and WPS buttons at the same time for around 10 seconds until the drive reboots and the Power and Battery Status LED flashes white.
2. Wait until the Wi-Fi LED is blue before reconnecting.
For more info, see complete online manual: