I’ve used plenty of project tracking tools over the years many of which I detested and a few I was OK with. AgileZen was a pleasant surprise when I came across it and I wrote a review and lobbied for using it at my current company as a Kanban style lightweight tool. It worked fine for us for a year or so, but gradually we noticed it was getting no love. The UI in tools like Pivotal Tracker were getting more responsive and event driven and AgileZen was stuck in the old request response cycle with a smattering of AJAX. Eventually it was obvious to us that it was dead software walking.
Rally Software promised that the beta would improve everything, but in the end they never released it. I’m sure it was a business decision where they didn’t see enough upside in improving it and decided to just eke out a profit with the current dwindling subscribers.
We ended up back in Pivotal Tracker which has served us well, but I still wish there was a nice Kanban style replacement for AgileZen.