It is beautiful app with many integrations(Zendesk, Jira, Trelo, Slack, etc) and many features which helps you to conduct research, prioritize what to build next, communicate plans and progress.
Hubert, the CEO of PB, is also very active on Medium where he writes about product management - https://medium.com/@hpalan
Full disclosure: I helped them get started (supplied some early coding time).
JIRA integration is effective and is bidirectional.
When it is necessary to provide timelines that allocate not only dates, but effort in terms of hours that be mapped to cost, it beats MSProject. More efficient, more flexible and the trial period is sufficient to make the leap into a proper Agile tool like Trello,JIRA, orAsana via Zapier.