I've been buying microfiber cloths from TV ads for a while, and have been generally happy with them. However, they tend to be more expensive than I like, especially since they sometimes get shredded while cleaning sharp items (cars, tractors, anything with snag-inducing edges) or just plain too dirty to clean (engines!). I bought a box of these Zwipes when they were on sale at Christmas, and split the pile between a main house and my weekend cottage. They've cleaned everything from cars to boats, motorcycles to ATVs, windows to floors, walls to pictures, and mopped up stains from spilled fluids of all types, as well as spilled fluids from dogs, all with aplomb. And they are remarkably strong, too. I have manage to shred two in all this time, and both were really dramatic incidents. I even use these for cleaning the guts of my computers, as they leave no messy lint behind.
All in all, I've been happy with Zwipes, so much so I'll be placing another order to put a few where they still don't exist around the house and vehicles. For routine cleaning they are great, and for heavy-duty scrub-till-they-rip, they're priced low enough I don't mind. These are handy cloths, and will replace all the other "As seen on TV" cloths I usually bought.