Do you have to think twice!

The price-performance ratio is right, if you primarily photographed up to 200mm. After that, it is really muddy, no matter what aperture. My copy has also its sweet spot at 300mm unfortunately actually only at f11; with whom ISO values ​​you have to operate there, it is clear. Overall me but the image quality in the long term can not convince them, especially at 300mm (and at a 70-300er wants you the part, too often use so!), But also in the rest of the focal range. As I said, for the price it is OK, more but also not really.

So if 200, - can pay more, but should please be sure (I have added myself now) for Tamron 70-300 VC USD grab! This has a great image quality, a fantastic image stabilization (3-4 f-stops in practice!) And a ring-type USM with FTM. With 300, - the equipment is at least as a value-for-Pops as the Sigma here. Who is a little scarce on cash, get with the Canon EF-S 55-250mm IS also a value-for-Pops with recognizable better imaging performance like this Sigma here (but slightly worse than the Tamron, also the image stabilizer is not as good and it does not have USM).