I was a long time Window Maker (not Windowmaker, the world's leading software for... something else) user for a long time as well, but finally jumped ship to boring old KDE.

It finally acquired most of the essential window management features of WMaker, such as Meta-R/L-Mouse to move or resize the window by clicking anywhere into it or shading windows.

However I still miss selecting multiple windows with a rubber band and then moving them to a different virtual desktop together, or the dock apps. I still can't find a proper widget which displays the network activity or something like wmforkplop to show the general system load.

wmaker + xfce destkop / file manager (can hide the desktop itself to the dock :D )