That was true for some time, but they're making me miss Bugzilla now. I spend increasing amounts of time just watching Jira load it's ever more bloated UI.
I think it depends on how it's configured and on the team's workflow. It really sucked at my second to last job, but at my most recent job it was reasonably usable, in that about half the time it was better than a comparable tool like Pivotal Tracker or Asana, and about half the time it was worse. A good and bad thing about it is that it isn't a typical single page app - good because it has fewer glitches and bad because it is more tedious in some places than Asana or Pivotal.
I have a lot of respect for Pivotal Tracker. It's a really elegant design, it is just missing a good detail view on issues, like GitHub's with history, comments, convenient deep linking, markdown, syntax highlighting, integrations, etc. Trello has a good detailed view for its cards, but not as good as GitHub.
I disagree, if the project is organized the way PT is intended, it's nice. If you have too many cards, or too much information with each card, it gets cluttered, and handles clutter worse than JIRA or Asana.
Having used both HP QC and Microsoft Team Foundation Server (the successor to VSS) for issue tracking, I have to say that Jira is better than TFS is better than QC. The big problem I ran into is that many teams had different fields and TFS and QC showed them all. This is a huge problem when there are well over 100 teams.