Sun 17-Feb-13 02:35 AM | edited Sun 17-Feb-13 02:41 AM by Omaha
FWIW, I've had the 18-200 for some time now. Its totally amazing. If I'm doing "walking around" shooting, its the only lens I even think about carrying. Ok, maybe I'll toss my 10.5 fisheye in my pocket just in case. Maybe. The 18-200 is a truly life-changing, do-it-all, the-only-lens-you-will-ever-need unit.
I recently broke mine. It still works, but its wounded. If it decides to stop working, I'll probably get the 18-300 to replace it. I've never tried one of those, but for essentially the same money and only a small penalty in weight and size, why not go for an extra 100mm of reach? If it sucks, just unload it on ebay and get an 18-200.
If I were in your shoes, I'd go for the 18-300. Actually, if I were in your shoes, I'd stick with what you've got. The only thing one of these other lenses is going to give you is more reach. You have 105 now, which really means you have about 150 (with the DX crop factor), which really means you have around 300 when you figure you can re-crop later as well (your D7000 has plenty of pixels to allow you to make some severe crops...unless you are planning on gallery sized prints, in which case you should be in the Hasselblad forum anyway). That's a lot of lens you have right now.
Back to the subject, if you decide to go ahead with some new glass, about the only thing bad about the 18-200 (and from what I gather the 18-300 is worse) is distortion (either pincushioning or barrel) at various points in the zoom range. Can't be helped really. You're not going to get ridiculous zoom ranges like this without some compromises.
The great news is that its easy as can be to correct in your RAW processor. Another reason to shoot RAW right there!
BTW, I forgot about these images....
These were taken with my D7000 and the 18-200. My point here is to show the insane resolution the D7000 has, and the resulting deep crops you can get.
This first one was from these corporate guys doing a "heart healthy day" thing downtown. They had this big banner and they invited people walking by to sign it:
This is a super-tight crop from the same image where you can clearly make out my signature:
My point is that even if you don't "get there" with your initial image, you have a lot of room to crop down and pull out the image you want.