>>> I can alt-click a window to move it in Xfree even if the application is blocking and I happen to click on a portion of the window that the application itself is responsible for drawing. Right?
>>Right: that's server-side decoration.
> No, that's window management.
In current systems server-side decoration imply server side window management, so I'd say you're nitpicking, but yes that's server side window management.
> [cut] a good compositor can interpolate frames and keep the resizing smooth
Not sure this would be so good: the client already took "too long" to answer and then the animation between both frames would add also some delay..