why not getting the 70-300 VR to get a complete range from 18 to 300mm?
purchasing hte 18-200 VR would most likely replace for ever your 18-70mm.
cheers
It really won't be an overlap, the 18-200 will eliminate your need for the 18-70 completely. Since the 18-200 VR is such a gem and you will want to zoom past 70mm so frequently, consider getting the 18-200 and selling the 18-70 if possible. Changing lenses is a pain, especially with a digital SLR since each change increases the chance of getting debris on the sensor. You won't need to change lenses much with an 18-200, and you will love the lens.
I wouldn't keep both because they're too similar in intended purpose. I'd opt for the 70-300VR for similar (or even less) money... very much underrated performance and an excellent compliment to the 18-70.
I would say it depends on what you need the lens to do. It's not just a question of available focal length. The 18-200 VR is a fairly decent general purpose lens in good light. The maximum aperture is f/3.5 and the softness at that aperture is very noticeable. I would never want to have to use it for narrow depth of field shots, nor critical landscape work due to the softness and distortion this lens can generate. The image quality drifts about quite a lot as you move in and out of different focal lengths. Still, if you are out and about in good light and don't mind shooting at or around f/8 - f/11, it will give you excellent results and a wide range of use. If I know I'm going to be indoors and/or needing low light pictures, the 18-200 VR comes off the camera.
