Several buttons don't work. Messages are missing, but the "Restore now" button does nothing. Not good at all. In comparison no missing messages on Facebook or the phone messenger.
Works, but if you look at the GitHub there are issues. It's kinda sorta maintained, but don't expect to do any calling. However, it's more than suitable if you need a basic desktop client for Messenger.
It is working well now. There are no delays. I have had worse experience with windows app-store version ;)
I don't know how well it handles audio or video calls because I haven't used it for those. It's great for text and images - nice alternative to a browser/app.
It's completely useless in recent times. During a call the screen after a few seconds goes completely white, the other party's voice is lost, the program does not respond to anything.