I know it isn't what the OP has asked, but I had the 18-200 Nikkor, and then replaced it with the 18-300 Nikkor (for the Olympics).
The 300 had appalling chromatic aberration. I took it to a Nikon dealer and asked if Nikon could look at it. Apparently it was within the tolerances for such a superzoom. Hooray for software correction...
It was entirely practical for what I bought it for*. If it wasn't for the Olympics, I'd have stuck with the 18-200, perfectly good for general walkabout lens.
*Some rowing Gold Medals. Weightlifting. The last gold medal ever in the stadium, presented to a future murderer.