I confirm the other excellent reviews. The web is full of studies tecniques about it I will not repeat, I do not have the technical capabilities of faires accurate testing. By cons in my opinion, is subjective! it is one of the best zoom manufactured to date all brands! only primes are even better (50mm f1.2 and 85mm f1.2)
Since I have it quite over my case (5Diii) that happiness! highly recommended despite the price! photos and good fun.