This is subjective, of course. Mostly true, but still subjective. She’s not wrong about the speed increase: it’s mostly linear by LPI, as in ~400 lpi takes about twice as long as ~200 lpi, all other settings being the same.
Here’s something that’s a bit more objective:
Your best bet is to follow @eflyguy’s advice: test, test, test. It’s the only way you can be sure you’re satisfied with settings.