Earlier quoted context omitted.
Can you give some examples of its power and customizability? What does JIRA do that for example Trac can't? (Trac can often be customized with 10 lines of simple Python (or CSS, HTML, JS) dropped as a single file into the plugin folder and you're done. It's the hacker's bug tracker. And it's fast and quite easy to use. I wonder why it's not more popular anymore.)
I've never used Trac for tickets. My first introduction to Jira was replacing 5 different in-house ticketing systems covering systems, desktop support, to software development. Here are some of the things I've noticed that I haven't seen other ticketing systems do as well; each department's tickets had their own fields that were unique to them, you could pass a ticket department-to-department with a clear interface t…
The default Trac search is very simple, sometimes maybe too simple. There's also the Ticket Query UI for field-based searching, which I use very often and quite like. Plugins for using solr or whoosh search engines also exist, but I haven't used them and don't know much about them.
I also recommend the auto-completion plugin: https://trac-hacks.org/wiki/WikiAutoCompletePlugin