Very usable, but you have to get over the hurdle of figuring out good FVWM keybinds first. I'd recommend wmaker instead for an average joe. Some jank with Xinerama (menus appearing on the wrong monitor), xinput (cursor snapping), general Motif shenanigans and interface bugs needing soft-restarts which there is a convenient button for. The upside is you get a really good theming engine and prettymuch everything can be changed.