There are so many possible reasons for images to appear to be soft so it will serve you better to isolate the nature of the softness so it can be attacked methodically instead of looking for general tests. When the D7000 came out, a lot of people complained of soft images but most solved their problem with a little more practice or revisiting long forgotten fundamentals. Can you post some typical images that illustrate the problem you are seeing?
How are you viewing the images, at what magnification and viewing distance? Do you get ANY that are sharp? What shutter speeds are you using and do higher speed make a difference? What post processing are you doing and with what software? Do LiveView or a tripod make any difference? Does the ambient light level make a difference and what about when using flash?