I've done papers and "books" in latex forever (don't want to say how long). At the time, I was a troff refugee, having gotten annoyed with troff on unix after a few years.
when I was at lsub last may, I got used to their nice scripts and such and now would much rather do short papers in troff than anything else. My new rule is < 20 pages, < 1 chapter, no need for complex math, do troff. Else, do latex. Part of the reason is being that the open source community has, as usual, come up with 50 ways to do anything in latex, most incompatible with the other, and in many cases latex and pdflatex are mutually exclusive: latex and pdflatex either fail to produce the same output, or, worse, can not accept the same input. tex/latex, once clean and small, are now a beast, like unto most other open source stuff nowadays. Troff has the virtue of having changed little in that time. Now if someone can do a set of IEEE macros for troff .... Irony alert! The Bell Labs journal now requires submissions in *word*. ron