Upload & Sell: Off
Marcelo, sorry I should have added that I had the x1.4 teleconverter on as well. The advice I received prior to buying it was that it would be a better combination with the 300mm than the x1.7 and certainly better than the x2, sharpness and IQ wise
Auto focus is very fast (well, I used to use a very old 70-210mm so anything would impress me after that I guess )
Haven't tried tracking anything with it yet - I almost tried it on some butterflies in flight, but it was a bit long and heavy. Good for flowers too as it throws the b/g oof nicely.