Lens suggestion - prime, or?

Well I wouldn't have thought so either re. the filter.  I did make sure it was clean, but thanks, that could be an easily overlooked obvious point.  The image quality isn't awful, it's just not as good as the 55. Maybe I'm just spoiled there.  (At least I think it isn't as good.  As I said, I should shoot the same image with both lenses to make sure that's actually the case)    But it was suggested to me earlier also (I got sidetracked and didn't get back to the project) to make sure the filter doesn't have anything to do with it, and I suppse seems like a good idea - remove an extra variable.

I got that used 18-70 along with the camera, just as an "I dunno, sounds ok" for a first lens.  And it may be just fine.  I just would like something faster, at least sometimes, and the only fast lens I have is manual focus.  I think my eyeballs are getting older, haha, and since the D7000 has that spiffy autofocus system, I guess I would like to take advantage of it more of the time.