JIRA with Kanban (Greenhopper)

Recently my work has becoming more and more project management oriented, so I have been reading a lot of books on the subject.

At the moment I am deeply interested in these two concepts:

• The agile software development methodology Kanban
• The psychological theory of Flow

I want to start bringing these two concepts into my team.

As I am using JIRA to manage my teams tasks, I am considering to buy the Greenhopper plugin which offers Kanban support.

Before I do so, I’d like to ask the community if anyone has any experience using Greenhopper for Kanban.  Any positive/negative experiences to share?