So, I'm not a user of KDE/Gnome, so let's see how far I can go with Wayfire.

1. No systray icons: Audacious, nm-applet, quiterss, kdocker and many others - all don't work, speaking of NetworkManager: basically I cannot start/stop network connections using UI at all
2. Thunderbird starts and then freezes for good 15 seconds
3. Firefox by default starts in XWayland, needs MOZ_ENABLE_WAYLAND=1
4. xterm doesn't work (yeah, I need it sometimes): xterm: Xt error: Can't open display: wayland-1
5. pavumeter doesn't work: ** Message: 12:08:29.135: Bad parameter
6. Global shortcuts don't work anywhere other than in Wayfire itself.
7. In both Firefox/Thunderbird the keyboard sometimes stops working altogether as if the keyboard focus gets stuck somewhere.

Sorry, this is complete and utter crap and don't tell me about Gnome/KDE 5 - I dislike both.