The primary draw of engineering paper is not that it looks cool or lets you fit a ton of information onto a page, it's that you can erase on it forever without erasing the lines.

Engineering work, especially if you're drawing schematics or doing a ton of math, is very prone to errors. I make mistakes all the time on my work for various electromagnetics problems or when sketching out some computer architecture problem while being a teaching assistant for a computer engineering class. With engineering paper, you can whip out your big white eraser and scrub that page clean. The paper tends to be sturdy, so it stands up to erasing well, and you can keep using it until you wear clean through to the other side of the sheet.

Engineering paper is pretty reasonably priced, and while it'll make you look strange if you turn in assignments or such on it in a non-engineering class, you'll use much less paper because you won't be throwing out sheets and wasting them when they get too erased on!