The current v0.1.0-beta looks very good. I only wish it came with a bar itself instead of relying on external programs like swaybar, or at least a working preconfiguration for swaybar that fits to most of the gnome-apps regarding the look and feel.
I used PaperWM a lot, but then it broke too often with every Gnome release. I havn't looked into the latest PaperWM. This Niri looks more promising and seems to have the basics sorted out. I have to give it a try despite the additional time needed to configure swaybar.