These are pretty competitive, and to recommend one over the other would require understanding your usage. Also, what other tools you use: for instance, what do you use for Issue-tracking, or for build pipelines. In your case, since you are already using Bitbucket, the question would be: do you have any current pain-points? And, on the other hand, do you already use Atlassian's JIRA, where you'd benefit from the tight integration? So, though I would not recommend one over the other just in general,. But, if Bitbucket fulfills your current use-cases, then there seems to be little motivation to move.