While it may seem overblown, it's absolutely RIDICULOUS how fast it flies on contemporary systems, and even older ones.

One can also omit most of their other apps, with the exception of KWIN, drawing the desktop and its window decorations, and konqueror, the filemanager, and the things managing the menu(bar(s)), applauncher.

Using modern apps for the rest, like anywhere else.

And have them styled, themed however you like. With a few mouseclicks.