I'm attracted to the tangle option because the normal latex export seems to take everything in my .org file, e.g.,
* Introduction
LaTeX is a document markup language and a document preparation system
for the TeX typesetting program.
#+BEGIN_LaTeX
\begin{eqnarray*}
\hat{f}(x) & \propto & \sum_{\nu} \frac{|F(\nu)H(\nu)|^2}{|N(\nu)|^2}
\frac{G(\nu)}{H(\nu)} e^{\frac{2 \pi i \nu x}{N}}\\
& \propto & \sum_{\nu} \frac{|F(\nu)|^2}{|N(\nu)|^2} H(\nu) H^*(\nu)
\frac{G(\nu)}{H(\nu)} e^{\frac{2 \pi i \nu x}{N}}\\
& \propto & \sum_{\nu} H^*(\nu) G(\nu) e^{\frac{2 \pi i \nu x}{N}}
\end{eqnarray*}
#+END_LaTeX
will result in both the * Introduction blurb as well as the stuff between the tatex "structural elements" being exported. With latex babel I can tangle and get only what I want. This is handy if I want to throw around a lot of chatter and extraneous stuff that ultimately I won't want in my final document. We might call this "annotations a la orgmode." But, yes, then I don't get the built-in orgmode latex support that comes with a regular latex export. Please advise if I'm wrong on this understanding.