Recently, I gained the ability to perform reviews of other user questions and answers. During my first steps I did not pay attention on the check-box "User edit was helpful" when reviewing and improving other user's edit.
This might be due to my subjective interpretation or lack of experience with the moderation tools in StackOverflow, but I think that it is not easy to see that checkbox, especially when editing a long post. Therefore, I came to the idea of removing it and using 2 submit buttons, like these:
[Submit and Accept user edit]
[Submit and Discard user edit]
Of course, better-suited and shorter text can be used, I came up with these on the fly. The idea is that the (junior) editor will understand that by improving other people's edit attempts, one should also decide whether to give them a credit or not.