In response to the last two comments regarding my suggestion that perhaps Robert would find more versatility in buying two lenses -- a 16-85 and a 70-300 -- rather than the 18-200:
This was simply my suggestion. I've shot the 18-200 and although it does make a nice, one-lens solution for travel photography, I've found it to be less than optimal in terms of image quality than lenses with less than a 10x zoom range. It's simply optics -- you can't produce a lens of that zoom range that's sharp at all focal lengths, light weight, fast and inexpensive enough for consumer use.
That's not to say that a competent photographer can't make excellent images with the 18-200. You just have to realize the limitations and trade-offs you have to make with a 10x zoom, over a 3x or 5x ratio.
The purchasing decision ultimately boils down to the type of shooting you do, your budget and whether one-lens convenience is more important than packing several lenses.
I own both a 17-55 f/2.8 and a 70-200 f/2.8. The IQ of both lenses is outstanding. But when I need to travel light, the 16-85 and 70-300 can adequately handle just about any shooting situation and subject.
As the old saying goes, "you pays your money, you makes your choices."