After years of using Axosoft OnTime, we decided to retire it and to move all our bugs/feature reports into Atlassian JIRA.
The main reason for selecting Jira is its perfect integration with Git. For years TatukGIS used Subversion (and still we use it to maintain the DK 10 & Editor 4 products), but all new development is now stored in Git. Furthermore, Atlassian offers a perfect Git solution called STASH which makes all branching and other code management tasks much, much easier and significantly less time consuming. It is worth to mention that JIRA integrates with Subversion as well. Therefore, from this single application, we have a view to all our past, present, and future code activity, including Kanban and Scrum wallboards.
A side effect of moving to JIRA is all existing feature request or bug reports had to been converted and renumbered. The Release notes now reflects a new numbering scheme that is applied even for old releases. If, however, you will mention an old bug identifier in your support request - we will still be able to easily find it.
Furthermore, our existing Continuous Integration solution just reached its limitations. So the probable next logical step will be to implement Atlassian Bamboo CI server. At that time we will finally have a single, integrated environment for all our code management & compilation needs.