The Windows Installer format is very poor indeed, but WiX adds too little to improve the situation much. Most people I know have created Python scripts to add more layers of abstraction to make installers easier to manage. I wish WiX shipped with those abstractions. At the moment, WiX feels like a box of parts for a kit car when I only need to adjust mirrors and change radio channel. Documentation adds to the frustration, because while it tells you details about specific parts, it doesn't offer a broader view: how parts connect to each other to form a drivable car. So you're left guessing and improvising, and you introduce bugs every time your intuition doesn't match how things really work.