I am a JIRA fan and i hate TRAC. Tracs interface seems to be utterly useless and it is not easy to customize it without spending a significant amount of time for that.
JIRA is very different. Its interface is clean, flexible and you can easily create groups that have nothing more than a Type/Title/Text-Form to create an issue. I found that a very imporrtant feature as my old company used it in order to communicate within and beetween departments as well as with clients.

So how does all that relate to Thoughtworks´ Mingle ?

• Well, a coworker of mine - fighting with Trac again - asked, if JIRA had something like a TODO List;
• I asked myself, if the 'Issues' can be planned easily, or if i have to take an ms-project alike for that;
• and my Boss asks for Transparency with the department.

Well, a little too much for Jira, right? All of that can be done, i´m sure - but it will not be hassle-free. Admittedly, JIRA is much more, than a bugzilla like Defect Tracking Software, but i just did not feel like this was all i needed. Luckily, i stumbled upon Mingle. I just had a few moments yet to use it, but from what i´ve seen, it is incredible:

Clean interface, total customizability, easy data-im/export, release planning, Scrum´s Sprint Backlogs, SOtry-Cards as well as classic Defect Tracking and a WIKI with great reporting options !

Not, that any of this is absolutely unique, but i´ve never seen a Software that complete, yet flexible to do what i need it to.
If your looking for more than a issuetracker, you should consider it.

Note: Mingle is not free, as soon as your team get >5.

• Mingle
• Atlassian JIRA
• Trac