So after looking at the full sized JPEG, I'm somewhat astonished that the image is ISO 1600. There is just
too much sharpness killing noise reduction happening in that shot. Which camera are you using?
Update: a very effective, surprisingly cheap, and not too inconvenient way to mitigate resorting to high ISO shots is to use a monopod. Gooshin bought me one for my birthday (I think!), and although I don't carry it around much, the times that I have, I've been happy with the results it has given me. Here are two examples from the same location: it was actually darker than it seemed, and hand-holding was not an effective option: