aappezzuto, actually, it's quite easy to make different appearance selections in LaTeX --- look up Peter Wilson's memoir documentclass for a very nice implementation w/ an excellent manual (ob. discl. I made some suggestions to it which were accepted). See also the TeX Showcase
http://www.tug.org/texshowcase for examples of the variety of document which can be done w/ LaTeX
bsandersen, my big complaint w/ groff, troff, lout &c. is that one is giving up significant flexibility in comparison to what TeX can achieve.
ath, the problem is it's not just a matter of marking h&j points, but of choosing good line breaks, and h&j is sometimes dependent on which part of speech a word is used for, so unless one is going to mark up every sentence for object, verb, direct object &c. it's not going to be possible to mark things up compleatly.
William