Paul, upon re-reading, I didnt respond regarding "is more forgiving of unscheduled reboots due to power outages."
With regular windows, using a UPS (Battery Backup) with shutdown software (like APC's PowerChute or open-source NUT), you can get an orderly shutdown when there is a power outage. All the AC-powered observatories I've worked on have an APC SmartUPS or BackUps Pro unit, that provides battery backup, and orderly shutdown.

With Windows Embedded, the OEM can place key components of the operating system into non-volatile storage, preventing them from being updated. e.g. FlashROM. This means that you won't get corruption from viruses or files accidentally being overwritten. Powering on again, you get the same clean OS. However, the applications can still get messed up, unless you build the boot image to include these as well.
In POS devices or things like Keysight Oscilloscopes and test equipment, since the core applications never change and are incredibly well tested, you include the OS, drivers, and applications, as well as a lot of the configuration in a boot image. Then you have to allow the user to make changes to user-specific values in volatile storage (e.g. IP address of the network card, user names, passwords, and operating parameters - e.g. if astronomy, lat/long/altitude, timezone, etc).
It's a big job to do this and get it right, and usually only makes sense if you are making thousands of machines.