Maximize and Restore Down are unreasonably slow if the Restore Down GUI size is small.
I run Windows 7 and I have two monitors and often switch Quassel between the two screens in Maximized mode by right-dragging the Maximized Quassel window over to the top of the other screen which auto maximizes it back. While being dragged the Quassel Window changes to its Restore Down size. With the current version of Quassel this operation can take up to 5 seconds to complete from Maximized on Screen #1 to Maximized on Screen #2 and responsive. Every other application I do this with takes as long as it takes to drag the mouse across (250ms).
I have determined that if I change the Restore Down size of Quassel to something large (at least 60% screen coverage) the time for the above operation is about 1 second and very jaggy (the Quassel Window doesn't always stay in the dragged state). During part of this time the Quassel Window still often doesn't keep up with the mouse, so my standard switch screen motion doesn't work.