I've been using GitLab myself and suggesting it to any clients with the proper infrastructure. When I found GitLab I tried it out, and finally ended up moving my SVN to Git (private projects). It's a great piece of software and I love the web hooks.
I think we can do better in our comparisons with competitors. I created an issue [1]. I haven't heard someone asking before about a comparison with Gitblit. Please feel free to email me at job at companyname dotcom if you'd like me to discuss it with your clients.
[0]: https://gitlab.com/gitlab-org/gitlab-ce/issues/10860
[1]: https://gitlab.com/gitlab-com/www-gitlab-com/issues/514