I am a Canon user, wanted a great all-purpose walk around lens, so bought the Sigma 18-200mm last year but was never happy with the results and found myself avoid using it and take my heavy Ls instead.
After reading a number of good reviews about the Nikon 18-200mm VR, decided to take the plunge and purchase the D200 and the 18-200 lens. Went to my favourite camera shop (they had a D200 and the lens available), but decided to test it against my Canon 30D+Sigma 18-200mm ….. and pleasantly surprised by the results. (VR on the Nikon was switched on during my test)
What was strange, I found the Sigma to be much faster than Nikon …. Can anybody explain.