It's a quirky mess, but none of the others, to my knowledge (and I've used most of them, which certainly includes Lout) do nearly as good a job typesetting. Lout does a bunch of things subtly wrong that I can't remember right now but that are very visually distinct, and troff is so far down that road I can recognize troff typeset documents at six feet from a glance.

Lout's equation formatting is especially primitive as I recall, and that is a huge amount of work to get TeX-like quality for. I am unaware of any system that typesets mathematics as nicely as TeX does.