Maybe not all the stuff, but I have seen many use Gitlab's docker & package registries, I think Gitlab's merge request discussions are miles ahead of Github's (threads without line discussions, can compare versions, etc), the test result integration is okay, we do use the issue boards a lot. We kinda use the deployments, but only for review apps. Merge trains are great too. There might be more cool stuff, that I either don't know about or have no use for, but in general they do provide some great stuff. (Not that Gitlab doesn't also have bad stuff.)