I was going to use this comment for some xmonad advocacy, but after reading the article, I think I'll be switching to Stumpwm. Haskell is nice, but Lisp is better :)

I would advise a little caution; I hear that Stumpwm has some stability issues.

That being said, I have never used it as a wm; so this is second-hand advice.

That's OK, 'cause I know Lisp better than Haskell. I don't mind hacking on software I use :)

I do love xmonad's test suite, though; that is its best feature, and it will be one that's hard to give up. Software without tests makes me lose sleep.