This past weekend, I was trying to grate a pile of parm using my Microplane (Classic Zester/grater, I believe) and had a heck of a tough time. It took me nearly 10 minutes and some serious elbow grease to grate ~2 ounces of cheese.
Do I need something more coarse? Is the gourmet/professional series any better? For the record, this thing works just fine for citrus zest and cinnamon. Nutmeg can also be troublesome. I can't imagine the thing is dull...I doubt I've used it 50 times.