I've found it to work very well. I particularly like how flexible it is and how well it is integrated. You can do some chatops, it even comes with a (not quite feature complete) slack clone (Mattermost), if you like. And, if it doesn't work, GitLab supports interfacing with Jenkins CI (but I don't think you will need to).

They also release updates and improvements at an incredible pace, so next month it will be even better.

Note, I am not affiliated with GitLab in any way, I just use it and love it.