Best lens of its class

This lens is perfect. It is sharp, it is easy to handle, it focuses fast, In summary all the good things that other people say about this lens are true.

Minor notes:

1. Hand-holding the lens:

In this department my only gripe is that focusing ring is directly below tripod collar, thus it is not easy to handheld this lens because you can easily move focus ring this way.

I solved this issue by getting an 'pistol handle' plugged to the tripod collar.

Also I usually use IS mode 3 (in this mode IS only works during the shoot) - I find mode 1/2 to make harder to find the subject in the viewfinder (usually flying bird).

IS is not quiet -  it makes a clicking noise, which is a bit annoying, even in mode 3, every time the camera (7dmkii) starts metering. this is annoying because many camera functions are only available during metering (expose compensation adjustment for instance)

The only exception I found to this is when I assign 'SET' button to change expose compensation when held - this awakes the metering but not the IS.

2. Lens hood:

Hood of this lens is awesome. While I didn't check its intended purpose of stopping flare, it does protect the lens from bumps and fingerprints.

The hood is covered on the inside with layer of black sponge, which stops dust from reaching the lens in addition to stopping reflections. Initially I was stumbled on how to clean it, since a brush doesn't clean it at all - the solution is to get an sticky tape for sofa cleaning - it cleans the hood perfectly.

I also like that the hood has lock button unlike many hoods which lock using friction only.

3. Other:

Distance scale is placed too close to the lens mount - camera covers it almost completely.

In summary I am very happy with this lens. I didn't even mention that is superb sharp because it is already very well known