Since now Jira is offering pretty wide free plans, it can compete with asana at small teams. And they have a significant advantage especially if you're working in agile methodology. Confluence is also a big advantage, and also comes with a free plan, so it's a pretty big thing.
But we had also talked about asana and used to work with it before a lot, but we chose to go with Jira, and it's pretty good for now.