I use i3. I'm talking about the entire X Window System not getting enough priority on the CPU when there is an oversubscription to CPU resources. I don't think it matters what the window manager is if mouse and keyboard events aren't even being handled.
Fair enough! I just haven't experienced that (laggy mouse and keyboard processing) before.
Well I've seen it but it tended to be RAM/memory rather than CPU originated.
Thanks for the update!
It's so light, even when a system is highly loaded, it still works fine (in my experience anyway)