I have been using LaTeX It quite often for quite some time now. It is amazing that I can use amsmath, amssymb, amsthm packages as well as the Xy-pic package quite effectively. I use inline categorical diagrams and this has been a great add-on, since I can just write my mathematics directly in the email.
Some queries: would it be possible to add support for tikz pictures using tikz package ?
Would it be possible to use commands defined using \newcommand elsewhere ?
This review is for a previous version of the add-on (0.6.4).