I bought the Borner Mandolin for my mom over 20 years ago and she never used it. She let me have it about 10 years ago and I LOVE it. It has 2 thicknesses, and I use it to slice tomatoes, onions, potatoes, and cukes, make french fries, hash browns, shred zucchini, carrots... it is so FAST, easy and convenient, and everything comes out even (unlike chopping free-hand!) I have shown a couple of people how to use it, and they went out and bought one themselves.
I'm that odd creature, a vegan who doesn't like vegetables. I always found them boring and bland, mostly because I grew up in a Southern home where veggies were boiled to death before a glob of bacon grease was added for "flavor." Prepping fresh veggies was too much of a chore. I picked up the Borner on the cheap during a trip to Hong Kong, of all places, and it sat in my drawer for a month. Once I finally tried it, it made vegetables so much easier to prepare! Onions? No tears. Home-grown tomatoes? No sludgy mess, just lovely thin slices. Ever had FRESH water chestnuts and bamboo shoots in your stir-fry? They are completely different from the canned-and-salted variety in both taste and texture! Now when I buy vegetables, it is with the reasonable assumption that I'll actually prep, use and enjoy them. Cleanup is also a breeze - nothing like my old box grater, which has the ghosts of potato salads past festering in the corners. This is one amazing machine!