Since you are using a D7000 which allows you to set the aperture with the camera body, you will be fine. The real disadvantage to a G model lens is that you cannot use them with a manual focus camera because you will have no way to set the aperture. If you can't control the aperture on the camera then the lens will always shoot at the smallest aperture.
There are numerous sources online explaining the shortcomings of the G models, none of which apply to you. One such source is here, which I read to double check and make sure I remembered what I read before :-). Note that it says "G eliminates many features with older cameras." (emphasis added by me).
Hope this helps.
I should have added more info about the G vs the D lens. I thought you were just asking about whether "G" mattered.
If I were you, I would read this review from cameralabs which actually talks a little about both lenses.
Note that the G model is also AF-S which means that it has the "silent" motor autofocus so it focuses quietly. The G model is also much bigger than the D model. Overall it seems to have better performance (although not in all situations) and I think I've read in multiple places that the bokeh is better on the G model (because it has more aperture blades?).