There seems to be something odd going on when resizing with Mod1+right mouse button: sometimes resizing is smooth, then it goes sluggish, then it becomes smooth again - all without releasing the right mouse button.
Also occurs on workspaces with only frames, with no actual windows in them.
Could be this is an X thing, but might be worth checking out if we can explain and perhaps even fix this.
Anonymous
I notice while resizing, other windows (terminals but also flash movies in firefox) freeze. Should check whether that's normal.