Is there any situation in which it would be easier to do things in LaTeX rather than XeLaTeX?
- Process old documents.
- Use old tools which are not compatible with Unicode.
- For faster PSTricks.
- Need PostScript output only.
- Use some specials that XeTeX has not implemented. e.g.
TikZ. (Now latest SVN
TikZuses a new system layer to support patterns and fadings in XeTeX)
Xe(La)TeX exhibits the bug shown in this question, so if you are doing something that requires writing tabs to an output file, it is more difficult to use XeTeX.
I myself encountered this bug when using the externalize functionality of
tikz, which writes a Makefile containing tabs. I find that the other features of XeTeX make up for having to hack around this bug, but if you aren't using those other features it is a pure annoyance.