I'm amazed at how sharp this lens is wide open.
This is a random photo I took handheld at a party.
70-200mm f/2.8L IS II at 200mm on a 7D
f/2.8, 1/60 sec, ISO 400
I'm attaching a 100% crop to demonstrate the detail right down to the pixel level.
If you look closely, you can see a reflection of the room in his eye revealing how I used the flash.