I'm not sure why Atlassian would acquire Gitlab when they already have Stash (which might be called Bitbucket Server now - but either way is a fully fledged Git{la,hu}b competitor)
We use Stash (and Jira and Confluence and a bunch of Agile stuff). Its... ok. Its a lot better than some of the other self-hosted repositories we tried, but there are some rough spots. Pull requests are a lot worse than Github, for example. The integration with Jira can be pretty cool though.