Just before Christmas I moved from DX to FX. This meant a review of my lenses. I ended up with the 24-120 as my general purpose lens and sold the 18-200 to support its purchase. I have been a fan of the 18-200 for years and thought I would miss the range, but surprisingly I haven't.
In FX terms I've effectively gone from a 28-300 equivalent to 24-120. I think I find the extra bit at the wide end (24mm FX behaves like 16mm DX) is proving more useful for me. I think the other factor is going from my 12mp D300 to the 36mp D800 as those extra pixels provide more cropping ability. If you shoot a D7000 you would not get this advantage as your DX image is around the same size as the D800 crop.
I think the image quality is a bit better on the 24-120 but I'm using a different body and sensor so it may not be a fair comparison. I was always very happy with the 18-200 in that respect, especially in bright conditions.
For anyone after a general purpose DX lens I would still strongly recommend the 18-200 as a great option. My wife still has hers and I think she would find the loss of zoom more of an issue.
In FX terms I've effectively gone from a 28-300 equivalent to 24-120. I think I find the extra bit at the wide end (24mm FX behaves like 16mm DX) is proving more useful for me. I think the other factor is going from my 12mp D300 to the 36mp D800 as those extra pixels provide more cropping ability. If you shoot a D7000 you would not get this advantage as your DX image is around the same size as the D800 crop.
I think the image quality is a bit better on the 24-120 but I'm using a different body and sensor so it may not be a fair comparison. I was always very happy with the 18-200 in that respect, especially in bright conditions.
For anyone after a general purpose DX lens I would still strongly recommend the 18-200 as a great option. My wife still has hers and I think she would find the loss of zoom more of an issue.