Seems like good advice.
Changing lenses is one of those things that I don't love. I don't know anything about the Nikon lenses at all. I am assuming that your current 18-55 and 55-200 are the kit lenses that came with the camera?
Pick the lens based on the type of photography you do. If you get the 18 - 105 mm, will it help you take better photographs or is it just so that you don't have to change lenses?
When I bought my first "upgrade" lens, I ended up getting one with the same zoom range but was a lens that I could shoot hand held in dark rides. For me, I based the decision on the type of photography I wanted to move into and picked the lens based on what I could (not) afford.
You may feel differently about lens changing. But even with an 18 - 105 range, you might still be changing lenses to get the extra reach into the 200 range.