From the useful-but-not-all-that-logical school.

It'd be nice to easily log work for a sub-task from the parent issue. One idea may be

1. to allow the % + graph section to be clickable (or parts of it), if you have permission to log work.
2. Clicking it will take you to the log work screen of the sub task
3. Redirects to the parent page when you're done

One random note also is that it'd be nice if the issue summary is displayed in the title / HTML window title on the "Log Work" screen (you have the issue key but no summary to remind your gold fish memory what the issue is)