In order to reduce excessive notifications, especially via inline editing of values field by field, we've disabled all notifications except for:

Issue Assigned
Issue Commented
Issue Comment Edited

The problem is that when Editing an Issue, changing the assignee or adding a comment is NOT sending a notification.

We are able to fix the "issue assigned" problem by removing the asignee field from the appropriate screens, forcing use of workflow or the Assign button/hot key.

We are not, however, able to fix the Issue Commented problem, because that field is on the Edit Issue screen by default and we can't remove it.

Ideally, either the Issue Updated notification could be further refined to allow specifing the fields that were changed that would send a notification; or, when updating an issue, Issue Assigned, Issue Commented, etc. events would also be fired off as appropriate so that asignees, watchers, etc. would be appropriately notified.