Personally, I also think, GitHub's Checks API, and it Github bots. Gives a much better experience compared to GitLab.

On a daily basis I am confused about how diff's are being rendered in GitLab merge requests, as it has a weird way to render ${blah} in strings in lines.

Also when you want to check if an issue exists in GitLab own repository, you always end up in some jungle of redirected tickets. Just now I got redirected to three different tickets , as they switch projects or something. Really annoying.