Starting with Chrome 70, PWAs are fully installable on Windows. Just look for the "Install <app-name>" menu item after 1/2 seconds from the page load. Fortunately, Chrome is using the verb "Install" and not "Add" as on Android on that menu. Thread ⏬ 
Most reports only talk about Windows 10 compatibility, but it works as well on Windows 7 and Windows 8.x. Chrome is not available as a universal app, so PWA installation won't be available on the mobile Windows versions, Windows 8 RT or Windows 10S.
The experience has a very similar UX than the one on Chrome 67+ for Chromebooks. Each standalone PWA gets its own themed window with document's current title, permissions and a drop-down menu to access website info (such as the SSL certificate) and "Open in Chrome."
In the Start Screen (W8/W10) or Start Menu (W7), all the PWAs go to a "Chrome Apps" subfolder. I don't like it 🤷🏻♂️ with the icon and the name from the Web App Manifest.
On Windows 10 there are some bugs, such as when you pin the icon from the Start Screen, it becomes a Chrome-icon Tile (both small and large).
PWAs don't appear in the Control Panel for uninstallation. Even, if you right click the menu option in Start Screen, the Uninstall option won't work. To uninstall the PWA you need to use the drop-down menu within the app's window, not within the operating system.
You can open several instances of the same app; they work as several tabs of the same URL within Chrome.
display: fullscreen and display: minimal-ui, will just be the same as display: standalone; display: browser generates no installation menu.
Compared with EdgeHTML-based PWAs on Microsoft Store, Chrome...
* can't specify minimum window size
* doesn't have a Back button in the window's UI
* doesn't use the Manifest's name for the Title
* uses the theme-color for the title's bar
* can Install from the browser
* can't specify minimum window size
* doesn't have a Back button in the window's UI
* doesn't use the Manifest's name for the Title
* uses the theme-color for the title's bar
* can Install from the browser
Compared with Chromebooks, Chrome on Windows...
* can open more than one instance of the same PWA
* won't offer "Add Shortcut" option when the PWA is not passing the criteria, or when "display" is defined as "browser"
* can open more than one instance of the same PWA
* won't offer "Add Shortcut" option when the PWA is not passing the criteria, or when "display" is defined as "browser"
Remember that most PWAs out there today are serving the Web App Manifest only for mobile devices so you might need to simulate a mobile phone before installing them today on the desktop. Also, most PWAs are not taking advantage of a custom Install button within the UI.
macOS and Linux support was officially announced for Chrome 72 (end of January 2019). An experimental version can be tested today enabling a flag at chrome://flags/#enable-desktop-pwas
