I photograph professionally and safely - a 70-200 L USM II Canon is better and worth the money, but it's just too difficult sau.
The 70-300 is for me a great performance with a long focal length and a very compact weight.
Of course you should use no later than 200mm a monopod if you would like to have sharp images, do the thing could not be stopped! If you understand his camera and understood with a bit of testing how the lens focuses the engine speed is absolutely fine. I take pictures so that concerts and am always gone well, even if it sometimes is very closely at f 4-5.6!
I highly recommend this lens highly!
