That lens is one of the most interesting and versatile lenses money can buy. You only need to carry around one piece of glass instead of 2 till 4. This means that this lens can stay fixed on your camera which on its turn means that you will have less chance of dirty and dust getting in your shooter and ending up on your sensor.
The image quality is very good and it suffers of lots less ghosting, lensflare and distortion. The built quality is also better compared to the 18-120. I'm definitely not a fan of the latter one.
The VR on this lens is yet again another superb feature. I don't think that they will ever start producing 18-200mm VR f/2.8 lenses, they would just kill too many others like for example the 70-200mm f/2.8 VR
I will buy this lens myself in the future. But at this very moment I can't order it with
www.cornevaniperen.com "Not availible for the moment"
Cheers