I compared this to the Nikon 18-200 VR:
1) The 18-135 is lighter and nicely balanced in handling, when mounted on the light bodies (like D-40). The 18-200 VR is much too heavy for the slight added zoom range.
2) The build quality is better than the 18-200. I got an 18-200 from the Japan factory, and it had dirt inside, inbetween lens elements! The 18-135 came perfectly clean.
3) The 18-135 has a smooth zoom barrel. While the 18-200VR has a horribly grinding zoom barrel, which sounds like it's got sand in it.
4) The zoom barrel stays put in any position, while the 18-200 does not stay in place (if you hold it vertical, it starts drifting - a LOT).
5) The focus speed is Much Faster than the 18-200. If you think this is slow, wait till you spend $ 700 for the 18-200 and have to wait while it hunts-n-pecks, focusing endlessly...
5) The VR did not give me any faster exposures. I composed the exact same shot with both lenses and got the exact same readings.
6) The only down side is the pincussioning. I agree with the other reviewers about this. But it's really only noticeable on architecture. Everything else about this lens overrides this blemish.
All-in-all, the 18-200 VR is nothing but Hype, for which they charge the consumer an extra $ 400. This is sales baloney.
I can't wait to get rid of my 18-200! I'm keeping this one.