Negatives:
+ High weight (together with the camera more than 3 kg)
(I have a SunSniperPro - belt with which it is fine.)
+ Locking ("Lock") of the lens as a screw cap and not like other L lenses with a slide button (Better solutions could be so simple!)
Positives:
+ Cover a large area without time-consuming objective change
+ Despite the weight are photos "out of hand" unproblematic on the tripod mount can hold the camera and lens well
+ In normal lighting conditions can make great pictures
+ Good Focus
+ Top - processing of an L-lens (expectations met)
+ Auto-focus is fast and accurate
Conclusion:
Perfect travel lens of upscale amenities. Anyone who is from the beginning about the heavy weight clear, can the high price for this lens to spend without hesitation. My expectations regarding the desired insert were even exceeded.