I own the 80mm - 400mm lens and while it has served me well, it is not a lens I would recommend general work. As has been already stated, it is an older generation lens with a slow, screw focus. Not that fast and not that accurate, especially at the long end. I pretty well only use it for wildlife shots.
If you find that the 18mm is too narrow; I would go to the Tokina f/2.8 11-16mm lens. The old version that I have is screw drive, but that has never been much of a problem, as the range of movement on an ultrawide is pretty limited. It is a very sharp lens; far better than the kit 18 - 55mm. Tokina has just announced an internal motor version, with no change in the optics. I personally find that I generally shoot at the 11mm end most of the time.