[marcelluspye]

I don't do my calculations/scratchwork in latex, but I know people who do, and take notes with it, etc. It's definitely got a learning curve, but once you've got it down it can be faster than writing by hand for a lot of things in mathematics (at least, according to some people I know).

[thearn4]

I reached this point in graduate school, though it took a few years for it to feel that natural.