10 out of 10 points and recommendedOptics, buildTripod collar
I bought my copy of this lens used in February 2009. I have shot around 25,000 photos with it since that time. I use it with a D700. I have TC14E and TC20E II teleconverters as well as a C-PL1L circular polarizer that I use with this lens. This is a brilliant lens.reviewed January 4th, 2011 (purchased for $3,100)
This is a big heavy lens. I mostly shoot motorsports, and I normally shoot with the lens on a monopod. It is capable of producing stunning images. It works very well with the TC14E, and reasonably well with the TC20E II.
I have had less success with the lens mounted in a tripod (Arca-Swiss B1 ballhead and Gitzo Mountaineer legs using a RRS foot) at slower shutter speeds (> 1/100). The tripod collar may be partly to blame, but at this point I am more inclined to blame my technique. Additional practice should let me refine that opinion.