Ok I am looking for opinions on walk around lenses. This means the type of lens that you have mostly on your camera and is the most versatile. Since I cannot afford a Nikon 17-50mm 2.8 lens, I was looking at the Tamron version of this lens. I have the kit lens (18-105mm) but I find myself rarely shooting at 105mm and for that my sigma is better. I could happily live with up to 50mm only. What are you using and what is the price/performance ration on those lenses? NOTE: I have a Nikon cam.