I recently upgraded from a D300 to a D700, so currently coping with having to upgrade my lenses.
I loved my D300, and also loved my Nikon 18-200, I actually miss it since moving to full frame.
Perfect holiday lens, but also general everyday all purpose solution. Never had a particular issue with the quality of images, never going to be as good as primes or pro-level glass, but more than acceptable in 95% of cases.
ONLY issue I had was lens creep, but I had older version and believe the newer ones have a switch to help prevent.