On the other hand, doing homework with latex means you'll have less cognitive load when using it for 'real' work later on. I would say it's more a good investment than a necessity.
>With mathematical homework, aren't you spending significant time ensuring that what you typed into Latex rendered correctly?
>[..]
>I could see it working for a lab report.
I think here is your answer: much depends how much your homework is like a lab report. I have occasionally had courses where the were only a few homework assignments and lecturer expected written answers typeset in LaTeX (or similar).
But I wouldn't bother either if I was the only person who would read my written notes.
I use it for homework when I often need to edit my previous work, or so that I can omit the proofs of "obviously true" lemmas the first time round, make sure the whole proof works, then go back and fill them in.
It makes grading easier, so you get better feedback---and more attention to substance.
Every graduate math class I've taken has asked for typeset problem sets; some have required it.
With mathematical homework, aren't you spending significant time ensuring that what you typed into Latex rendered correctly? (I.e., the edit-compile-look loop?) I sometimes omit parentheses or put braces in the wrong place, which causes the display to be in error. Introducing another step in the process seems troublesome, and would take me out of the "zone" of problem-solving. (I.e., handwritten copy -> Latex -> rendering vs. just handwritten copy.)
I switched from troff to Latex around 1991. The explanatory tables for the sprinkler system and the electrical panel for my house are in Latex. So, I'm a Latex-phile, just skeptical about this case.