Yes, Shadow Defender is not for everyone (like Linux, Chromebook or Chrome OS). It is ideal though for people who have pretty stable setup, and like to test/play with many kinds of software. There is one important limitation - the software has to work without restarting the system. This limitation can be the obstacle when installing some security programs (for example Comodo Firewall).
UPDATING - I go out of shadow mode once a week to do updates and let the system make conservation (1 hour a week).
PLAYING WITH SOFTWARE - I used to install/test so many programs and test so many system tweaks, that without ShadowDefender the Windows had to be reinstalled several times a year. Most programs can be installed in a minute, so some useful programs (that I need rarely) I install temporarily and use for some hours in shadow mode. If the program is useful and needed frequently, then I install it out of the shadow mode. If I want to play longer than usual, I do not turn off the computer, but sleep the system. You can use the Steam platform to install many games when in shadow mode (SteamLibrary folder on the second disk) - only games that require installing C++ or DirectX libraries need installation out of shadow mode.
COMMITTING FILES - I use two partitions: the system partition in shadow mode, and the second not in shadow mode. I keep the data on the second partition. I make the backup of the important data on the external USB disk. Committing big folders in Shadow Defender is a data suicide, it lasts toooo long and may cause some errors. I rarely commit files.
SSD - I use 4GB RAM for Shadow Defender cache (computer has 8GB total RAM). That amount of memory is sufficient for one day in shadow mode in Windows 10.
VIRTUAL_BOX - I use it frequently, so it is installed out of shadow mode, also the path of the image folder has to be changed, so this folder will be created on the disk that is not in shadow mode. Then you can use VirtualBox in shadow mode on boot.
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The above works for me.