Yeah, I find it a really decent WM -- I tend to think of it as a lightweight XMonad without having to learn Haskell to configure it.Spectrwm is nice. I've used it, without problem, in a multi monitor setup. I have a somewhat dated page on it--I wound up preferring dwm which seemed slightly faster, but my page, which is still, I think, valid is at https://srobb.net/spectrwm.html
As it happens, I've just finished implementing spectrwm's swap workspace functionality in fvwm3 -- great inspiration.