i'm a Nikon snob and will never "personally" toss a Tokina or Tamron on my camera.
......BUT, people are much happier with their 3rd party Tokina lenses than any Tamron.
one comes to mind - the 11-16 Tokina F2.8.
simply put, it's a stunning lens that outperforms the Nikon 12-24 that costs almost 3 times more.
that said, the 11-16 Tokina works perfectly with DX, but not for FX.