You need to bring back the check box.
When you have 500+ comments/corrections its time consuming to have to right click to mark each one. It was MUCH better before when you just marked the box.
In the latest update of Acrobat DC, we have modernize the commenting experience and at the same time, made it very clean and intuitive to use. As part of that, the checkbox is moved to the right click menu of the comment.
Open comment>Right Click>Add Checkmark
Please also note that both the sort and filter options are available for the check mark.
We are sorry for the inconvenience caused and will consider adding the check mark by default for future updates of Acrobat DC.
However there is one workaround to make the checkbox appear in one step by using the keyboard shortcut SHIFT + K .