I am now in the nice position to have nice glass and camera to play with. I have both the Sigma 24-70 f2.8 (HSM version, not the cheaper Macro) And the Nikon 24-70 f2.8 My colleague and me both prefer the Sigma lens on the D300 and the D3 over the Nikon Lens. The Sigma is short, stubby, heavy. while the Nikon is longer, similar weight. The camera just feels easier to handle. I have no doubt that the Nikon has better IQ in certain circumstances, but I hardly ever pixel peep any more. For me the The Sigma is a winner over the Nikon because I will never spot the difference in price in the picture. Hope that helps a bit Alan
finally gat a 24 70 nikon lens i was on the verge of buying a new Sigma when i was put on to a gent who had 3 of these for sale,(not sure where they come from but it's in mint condition), so i took the plunge and bought one of them, now £850 isn't cheap but i think it's well worth it.