I bought this hoping I could do a once-over on my rug that my dog had defiled within the first week of having, then to use it as a spot cleaner going forward. Do not make this same mistake...it is LITERALLY just a spot cleaner. Unless you're prepared to sit on the floor and go through several cycles of dumping dirty water and refilling the formula, etc. (I did, though, I wasn't about to rent a machine for a 7x10 and 3x5 rug (the rest of my house is hardwood or tile)...but that's not why my review is 4 stars. I just want to warn you about that...if you've got space to store an upright carpet cleaner and/or you actually have carpet, not just a couple of rugs, in your house, I would say go with that instead.
My only complaints about this unit for it's intended purpose are that the dirty water fills up far too quickly (or rather, it's capacity for dirty water is very low...half the tank still remains empty but it's actually full. Also that it uses a lot of solution to remove very little, so be sure to bargain hunt for all those Oxy solutions and Pet Removal shampoo/cleaners, etc. And finally, the brushes get dirty/clogged very easily which affects the suction.
Overall, though, it's a good machine and is great for a small spot or two at a time. It's a little weighty to be getting in and out all the time, but if you need something only rarely, it's great. I'm trying to teach my dog to stop peeing on rugs, so I feel like I'm constantly getting it out and wonder why I bother putting it away.
Positives...it's compact, it's easy to store, it's aesthetically pleasing (as far as little shampooers go), and it will get the spots up, even if they're a little old. The sooner you get to them, the better, obviously, but I was able to get out old spots with just a little extra elbow grease.