So I think, of a Marketing perspective, Canon sest planted. But for you photographers, know that this is a bargain! Rare are the objectives "L" at this price. Just think, you could have the barrel 100-400 Euros in 1000 on the occasion of market. Here you are covered for everything sports and wildlife. He's missing is you quun 50mm (Whether you have probably), and therefore, you are still pépettes to take a good Grand Angle, before arriving at the rates of the objectives "L" price "Luxuries".
Noise side: Same comment quavec the 24-105 canon of the series "L", I nentends nothing. The Canon plug for dB must be substantially identical. This is kind of the point of these engines "USM". By cons, every day, it does you no good unless BE Nature photographer photographing animals you do not want to arouse attention.
I summarize: great Construction dive very good, minimal distortion and great prices. The least that is the bokeh, but frankly, why on Telephoto zoom, and weight. This is not a goal for wimps. With approximately 1.4kg, if you add a box reasonably Full-Format as the Canon 5D Mark II with grip, it makes you at all 2,6kg to carry. Attention to cervical if you are crazy enough to wear it slung around his neck.
For examples of layouts and details, I invite you to see my review on photoexposition.fr