From my perhaps idiosyncratic point of view, the most obvious issues are these:
- "Displayed", as opposed to "inline" TeX looks very good in Wikipedia articles, but "inline" TeX usually looks about three or four times as big as the surrounding text, and that looks buffoonish.
- In "inline" TeX, simple things like a^b and a_b are formatted wrong: obviously in both cases the a should be at the same level as the surrounding text and the b respectively higher or lower.
- Making everyone use mathJax may be the solution, but mathJax still has bugs. Wikipedia needs more sophisticated behavior from mathJax than do other forums that use it, such as stackexchange and mathoverflow. For problems with the behavior of mathJax within Wikipedia, see this URL.
This post was posted by He7d3r, but signed as Michael Hardy.