Kaźmierczak is a Mathematician so his writings are of exactly the type that TeX/LaTeX were designed for. He gives some examples from one of his papers showing how it's possible to preview the finished product within an Emacs buffer while still being able to see the markup. This is, as he says, very useful.
He also mentions using
flymake with AUCTeX to have Emacs check your LaTeX syntax on the fly, and RefTex mode to manage your references and generate a table of contents to help you navigate through the document. He shows his configuration for using these utilities if you're interested in setting up a similar environment.
These days, as I've said before, I use Org mode for almost all my writing. The nice thing is that Org is easier to use but you can embed LaTeX commands within your document so you still have almost all of the LaTeX functionality available. If I were to write a longer paper with a lot of mathematical content, I'd probably fire up AUCTeX. Kaźmierczak's post makes me want to do that just for fun.
It's a great post and if you have any interest in writing in LaTeX, you should give it a read.
The post is from 2010, but Kaźmierczak has added updates occasionally so it's pretty much up to date.