It is big, it covers alot of ground, therefore it has large software product illnesses - complicated to setup, hard to master, tricky to optimize to run fast. However, it is a nice product for some heavy-duty task managing once you have it set up and running, absolutely nothing is horrible.

For a smaller project, though, I would roll your own to specific requirements, or would use a smaller package or product - because JIRA does everything and that could be too much sometimes.