Really the most egregious thing: Manual job runs. They're a first-class citizen in Jenkins, where it lets you make a rudimentary UI by having several types for

Really the most egregious thing: Manual job runs. They're a first-class citizen in Jenkins, where it lets you make a rudimentary UI by having several types for each variable (e.g. a selectbox). In GitLab the manual run just gives you a list of defined variables and a small text input next to each. Then there's dependencies between jobs which has gotten better lately but again it seems less developed compared to Jenkins. I also managed to kill the web UI with some of my pipelines when using dependent jobs because the javascript fails somewhere deep when trying to visualise the pipeline and the page just stays blank. Honestly it really depends on what you're doing. If you're mostly replacing automated builds and tests triggered by git changes then GitLab works just fine.