Just didn't want to invest in the Nikon 70-200 since I will mainly use it for portraits and some sports (I have the Sigma 120-300 2.8 mainly for sports). So I opted for the Sigma and after some basic "real world" testing I'm impressed. My son wouldn't comply so I have this silly tongue wagging shot. :tongue: D700 & 70-200 @ 1/125 f2.8 ISO 5000 (3200 pushed a bit over 1/2 stop in post using LR2) - basic tweaks, sharpened for web: 100% crop no sharpening at all - slight blur is either camera shake or subject movement since static objects are extremely sharp: This was a test shot of the neighbors van from about 150 feet. D700 & 70-200 @ 1/400 f2.8 ISO 400 - basic tweaks and sharpening for web: Crop of the model name, again no sharpening at all (license plate was sharp too but can't use it for privacy reasons): Here's a static shot with a closer object (still hand held and high ISO). D700 & 70-200 @ 1/250 f2.8 ISO 6400: Crop, again no sharpening: You can bank on even better sharpness on a tripod with lower ISO. This was just a quick test and I'm not too concerned with taking any tipod tests because I'm satisfied already. Corners look good, not seeing much vignette (none that bothers me), images are very sharp so far in testing - I just can't complain. If you're on the fence don't hesitate to save a bundle on the Sigma. BTW, I'm never exclude sample variation with Sigma so ymmv, don't hesitate to return and try for a sharp copy.