Nikkor 16-85 or Tamron 17-50?

Which one takes sharper photos and has a better IQ? I really like to have f2.8 from the Tamron, but i also like the zoom on Nikon lens. Would you prefer the f2.8 over the zoom?

The Nikkor is the better lens

Easy answer, Nikon 16-85 VR. What you lose in maximum aperture, you'll make up for with VR because you won't gain much with f/2.8 in that lens. If it's that important, you can find a used Nikon 17-55mm 2.8 for $900. I would not recommend either Sigma or Tamron's 17-50 2.8 zooms. I've used them both and I eventually returned them both. I own the 16-85 VR and it's a superior lens. While the reason most people consider those lenses as alternatives to "name-brand" is price, it really isn't worth the savings in the long run. Trust me.