We're a big Atlassian shop, and switched from Crucible to Bitbucket Server (then Stash). I do not get the sense that Crucible is the future as far as Atlassian is concerned - I believe they see Bitbucket Server as what they are going to focus on.
FWIW, with the latest releases, they've addressed most of the remaining features that were missing from Crucible, and I'm very happy now with the PR/code review flow in Bitbucket Server.
