I have tried both of them. They are both powerful on their own respect. Niri is still on its early days so things like floating window are a work in progress (last time I checked), but things like its window management is great if you can set up nice keybinds for the multitude of actions available and its scrolling behaviour works like a charm on laptops. Niri also has a configuration file validator that you can use before restarting Niri which is genius! One thing you might hate or love is the dynamic workspaces, workspaces are moved/renamed so that they are consecutive. So if you had four occupied workspaces ( 1 through 4) and clear workspace 3 now you would have three consecutive workspaces (1 through 3) effectively making workspace 4 now be workspace 3.
River is super fast because of how minimal it is plus it has some nice community layouts available to suit your taste better. Also the tag window management can be the fastest out there but can become hard if not set up properly. It was to cool and all but I feel it is more for power users and it totally overwhelmed me when I tried to set up stuff to set tags for windows and move them around monitors (and that when you move a window to a monitor it does not keep focus on it). The way I use Sway and Hyprland is to set workspaces for different monitors and it just feels easy for me to move windows around focusing(or not) the destined workspace. I think the best feature of River is to toggle any window on your focused tag, it really feels like magic.
Have you tried niri yet? What about river?
I have tried both of them. They are both powerful on their own respect. Niri is still on its early days so things like floating window are a work in progress (last time I checked), but things like its window management is great if you can set up nice keybinds for the multitude of actions available and its scrolling behaviour works like a charm on laptops. Niri also has a configuration file validator that you can use before restarting Niri which is genius! One thing you might hate or love is the dynamic workspaces, workspaces are moved/renamed so that they are consecutive. So if you had four occupied workspaces ( 1 through 4) and clear workspace 3 now you would have three consecutive workspaces (1 through 3) effectively making workspace 4 now be workspace 3.
River is super fast because of how minimal it is plus it has some nice community layouts available to suit your taste better. Also the tag window management can be the fastest out there but can become hard if not set up properly. It was to cool and all but I feel it is more for power users and it totally overwhelmed me when I tried to set up stuff to set tags for windows and move them around monitors (and that when you move a window to a monitor it does not keep focus on it). The way I use Sway and Hyprland is to set workspaces for different monitors and it just feels easy for me to move windows around focusing(or not) the destined workspace. I think the best feature of River is to toggle any window on your focused tag, it really feels like magic.
Hope that helps.