BugTracker is an excellent tool for tracking technical changes and issues in a development project - the ability to assign tasks or issues to an individual developer, then assign it back for review and finally closure helps ensure a great quality end result. While it's great for tracking development issues, it's harder to use for content changes and updates, and we've found other approaches to be more effective.
It may not be the best or easiest tool for collecting client feedback during staging and feedback cycles, since the user interface is very developer-driven. Designers, Writers, and Project Managers are able to use it effectively, however.