My dad got me this as a gift, and for the price (I've seen it in stores for under $20) it's quite a good little gadget. As long as you think of it as a broom/dustpan replacement rather than a vacuum cleaner, you'll probably be pretty happy. All it is is a series of round brush things that spin to sweep things up into a little bin inside. Very simple. It's a bit noisy, but for the price, I'm not going to complain. My one gripe with it is minor, and that's if you happen to sweep up a shoelace or something that gets caught up in the spinning brushes, your first instinct is to flip the thing over and pull it out. The moment you turn it right-side-up again though, most of the contents of the little bin falls out onto the floor! It's not much trouble to just sweep it right back up again though.
Oh and the really nice thing about this is the rechargable battery! It lasts a LONG time between charges (I've had mine for several months now and can go at least a couple weeks between chargings with light daily use). Also, it makes the sweeper cordless which is a big factor in my reaching for it rather than my regular vacuum whenever possible.
No attachments, don't really know about the warranty. Cleaning it is a breeze, you just have to remember to do it!
Also, not sure how well it works on carpet, as I've got all wood and tile. Remember, this thing is cheap, don't expect it to clean big messes. But for little every day ones, it's fine.