My only beef with it is the temperature. My mom has one, as does my mother in law, and they do 'okay'. I agree, it's like a slightly better swiffer. In reality, when the steam makes contact with the floor it's only about 100F (i.e., already cooling to the point where its basically hot water), so you could get the same effect spraying hot tap water on the floor and wiping it up with a cloth, this just simplifies the process.
I have a monster, the steam hits the floor at around 250F. This is more of a safety hazard, however, you don't wanna touch the bottom of this thing! YOWCH! (Speaking from experience), and more delicate floors may not appreciate the temp. It's also a bit more expensive, I got mine for $100 on Amazon, but it retails higher than that.
So basically, there ARE advantages to the shark, namely- cheaper, cooler (less cleaning power and virtually no sanitation power, but less of a safety hazard and less risk of damaging flooring), and... cheaper!
Not bad for the price. It's not the flagship steam mop, I don't know who was first but there are certainly alot better ones out there now, but it's really not a bad deal.