Self-hosted on-premise GitLab is much nicer to use than the SaaS gitlab.com instance.
A few years ago (when I used gitlab.com regularly), the hosted version was quite slow and felt like a buggy beta-testing environment. Not sure if it's better nowadays. On the other hand, I'm running two on-prem instances of GitLab for a few years now, and they've been working flawlessly and are fast. (One of them is now upgraded to the Premium plan.)
A few years ago (when I used gitlab.com regularly), the hosted version was quite slow and felt like a buggy beta-testing environment. Not sure if it's better nowadays. On the other hand, I'm running two on-prem instances of GitLab for a few years now, and they've been working flawlessly and are fast. (One of them is now upgraded to the Premium plan.)