Any point in keeping the 18-105VR if I have the 18-200VR?

Probably not, especially if you're happy with the 18-200. Here are reviews that indicate sharpness and distortion:

http://www.slrgear.com/reviews/showproduct.php/product/1281/cat/13
http://www.slrgear.com/reviews/showproduct.php/product/1221/cat/13

18-105 pros: it's sharper, has less distortion overall

18-200 pros: 106-200mm is not covered by the other lens. Metal mount (people seem to like that although I'm not 100% sure on that one), probably better build. Not significantly bigger than the 18-105.

You could probably get some OK money for the 18-105, especially if it is in "new" condition. If you were to keep the 18-105, most people would probably have to complement it with a 70-300 or something.

Good luck.