UPS delivered this at 8:00pm last night so I didn't get a chance to play with it until I got home from work today. Like all 3rd-party lenses I was a little nervous awaiting its arrival since there are always enough negative reviews online to put doubt in the back of your mind. But after noodling around with it on my D700 I am more than pleased with its performance. NIKON D700    ---    14mm    f/2.8    1/60s    ISO 800 D700; 14mm, f/2.8, 1/60s, ISO 800 And a 100% center crop... NIKON D700    ---    14mm    f/2.8    1/60s    ISO 800 Now to counter the excellent center sharpness wide open, the lens does flare like crazy with its bulbous front element... NIKON D700    ---    14mm    f/2.8    1/1600s    ISO 200 D700; 14mm, f/2.8, 1/1600s, ISO 200 And has some CA at the corners... NIKON D700    ---    14mm    f/4.0    1/640s    ISO 200 D700; 14mm, f/2.8, 1/640s, ISO 200 Upper left corner 100% crop... NIKON D700    ---    14mm    f/4.0    1/640s    ISO 200 But again, I love the center sharpness... NIKON D700    ---    14mm    f/4.0    1/640s    ISO 200 All these were shot as 12-bit NEFs and converted for web in Lightroom 2. Not adjustments made except to resize. Along with the Tamron (which I purchase new from Amazon) I also received a used Tokina 24-200 f/3.5-5.6 from B&H. This lens performs like most super-zooms with sharpness peaking about 2 stops from wide open. But as a replacement for the 18-200 I gave up in switching to the D700, I think I can live with it until Nikon get's back into producing non-pro FF zooms. 24-120 f/4 VRII anyone?