I try to buy things on GOG when I can just for the sake of diversifying my dependence on one company.
There are plenty of guides to setting up Heroic Launcher on the Deck. Once its set up, it’s easy to install games.
I’ve found GOG games to run perfectly fine, and cloud saves work perfectly.
Lastly, I saw some other people saying GOG doesn’t have the latest version of this game specifically, so definitely check that before buying.
I wish I knew this months ago! This knowledge needs to be spread around more.
Also, if your phone doesn’t show up on the deck, make sure to enable “show all devices”