1600-3200 see example
https://lh6.googleusercontent.com/-N...o/DSC_0015.JPG didnt bring any support as it was just supposed a short trip, had to head home for dinner. exif data incorrectly showing f4, should be 5.6 . Max auto iso set to 1600, 1/60s was far too slow for 440mm handheld shot. I guess I will miss having VR. Will be going down to bushy park on Saturday then Riat on Sunday.
Are you using the sigma 70-200 to shoot fast jets?
edit 2:
Just done some quick research on the sigma, very nearly as sharp and lacks weather sealing but its about £600 cheaper. Hopefully it will in bag by the end of this year. Currently priced at £627 from the same place I bought my 300mm versus £1220 for the nikon