I edited this thread, I just bought the Tamron over the Nikon 17-35mm F/2.8 primarily because I rarely shoot in the 17+ focal length. I am still curious how this lens compares to the Nikon. I only have the Beast to compare it to. I would really like to see the Tamron go against the Nikon 17-35mm (or 17-55mm) since I need to see what it can do from 17mm to 27mm. Performance My experience with the Tamron (compared to the Nikon), is that the Tamron, does not focus as fast. It's not as smooth or fluid. I think this is to be expected because I'm comparing it to a pro lens. The build quality is better though than what I expected and it actually is made in Japan too. But, it does not feel as rugged or tough like the Beast. I could see this being a problem especially for a photojournalist, let's say stationed in a war zone or someone shooting in extreme conditions. I did a test shot on another product earlier and felt that focusing manually gave me better results than relying on auto focus. Again, the time for it to focus is good but not as fast as the Beast (and for me to note that means there is a difference). I have never used kit lenses or consumer level lenses to know if the Tamron performs better. On some outdoor shots, when shooting landscapes, I noticed vignetting especially at 17mm (and sometimes even at 50mm) @ 2.8 -- I had the hood on and maybe that is the problem? I wonder if trying it without the lens hood will do any good. On some general outdoor shots, I noticed the lens hunting (is the right term?) for the proper focus. Although technical research is best, in my opinion, I noticed more CA on the Tamron compared to the Beast. I still have to do more testing though. But overall, this is a good lens in my opinion and is worth every penny. If you primarily shoot a lot in the 17mm wide range or landscapes that require wider angles than the normal focal lengths, I would recommend the Nikon alternative even if it cost more. It's like comparing apples and oranges after seeing it perform mechanically against the Beast (and I assume the Nikon 17-xx f2.8 performs almost the same). Especially on an assignment, you want a lens that focuses fast. But if you have time to spend to compose and not as critical on the performance side, the Tamron is a very good alternative. I bet clients won't even notice the difference in picture quality. But, if I eventually shoot a lot of wider focal lengths, I will invest in the Nikon. For me, although sharpness and image quality is important, I feel that the lens performance (and build quality) s as equally important. Sharpness at f5.6: I did a quick test shot (Japanese wooden doll) comparing it to the Beast at 35mm. I used aperture f5.6. The pictures are JPEGs straight out of the camera with no sharpening (even in camera), PP, etc. I unfortunately do not have time to test it in all aperture ranges and distances. Please note that I shot this in a controlled environment. It might be different when you are actually shooting out in the field; in an extreme condition; or have more time to spend for precision -- because performance-wise, the results are different. I also have another random shot of a helicopter flying by. No sharpening (even in camera), etc. or PP. This a JPEG straight out of the camera. Tamron 17-50 f/2.8 @ 35mm f/5.6 (100% here) Nikon 28-70 f/2.8 @ 35mm f/5.6 (100% here) Tamron 17-50 f/2.8 @ 50mm (noon time) Tamron 17-50 f/2.8 @ 50mm (noon time) - 100% *my old post* I rarely shoot wide angle but have been considering buying the Nikon 17-35 f/2.8 for situations where I would really need it. But, I can't seem to justify the cost of the Nikon especially since (again), I rarely use wide -- but there were a few occasions where I hope I had a wide angle lens. I've had an 18-200 VR but have found out in some assignments that the f/3.5-5.6 is not enough. I've researched Sigma's 18-50 f/2.8 but it seems the Tamron 17-50 f/2.8 has better and consistent reviews. Has anyone tried both the Nikon 17-35 f/2.8 (or the 17-55dx f/2.8) and the Tamron 17-50 f/2.8? What do you think about the Tamron lens? Is it sharp enough that it would be hard to tell if the pictures from both lenses were side by side? How is the color? And is it fast? Thanks in advanced for any input/feedback.