I don't have one but I've been researching this also, I found a lot of negative reviews on the Shark, mostly that it is cheaply made and that it leaves the floor very wet/slick. I haven't made a purchase yet but this is the model that I was thinking of purchasing:
http://www.amazon.com/McCulloch-MC-1275-Heavy-Steam-Clean...
It has excellent reviews and seems to be much more multifunctional because you can even use it to detail your car and since I'm expecting my first child, I'm expecting that my car will need a steam clean eventually. It even is powerful enough to clean your outdoor grill which I can't even imagine doing. I have wood and travertine floors so there are a lot of chemicals that will ruin my floors so I really need this and many people also stated that this model can steam for much longer periods of time then others that I guess run out of water and need to be refilled? Like I said, I haven't tried it but Amazon has reviews for every product out there so read up on those before you chose something and pick something that will suite your needs. Good luck!
Here is also a video from youtube:
http://www.youtube.com/watch?v=ItCqiBuxktI