Sadly this does not fix bugs. And the issue tracker of gitlab-ce grows and grows and the CI is not really stable.
The new permission model was great, but break stuff.
Unfortunatly at the moment me and my team is discussing to use gitlab + jenkins instead of gitlab + gitlab for vcs/ci.
just because webhooks + jenkins is way more stable than the gitlab way (and actually webhooks are push based, while gitlab ci polls.)
This is sad since gitlab ci was quick and easy, while even the new dsl for jenkins is way harder to get right. but we actually can't retry half of our builds.
Another way would be using the shell executor where we actually loose some functionality. (we use the docker executor).
I know your vision (and I think some ideas are great), but sadly I think too much centralization is harmful after going with gitlab since v8, somethings does not need to be reinvented by gitlab (they might just need a improvement).
The issue tracker is growing because we also keep feature proposals there.
GitLab CI doesn't poll the repository. The GitLab Runner does poll GitLab for new jobs. We're currently working on making sure that GitLab can deal with those requests more efficiently. Polling makes setting up Runners a lot easier for our users.
Not being able to retry half of your builds sounds very bad. Please contact support@ our domain and add a link to this comment to receive help with that.
It was a big thing to add CI to GitLab and we had a lot of concerns about it before we did so. But after doing it the improvements in the interface, CD functionality, Pages, review apps, auto deploy, and many other things convinced us that this is the right path.
GitLab will work with other tools but out of the box it will offer you a great experience. For the benefits of that please see https://about.gitlab.com/2016/11/14/idea-to-production/
My last note is on your mention of the growing issue tracker. The issue tracker is not only about defining bugs and problems, but also about idea exploration. To my knowledge the more GitLab will be known, the more it will grow. It is everyones best interest to let it flourish, but in an organised way. We are hard at work in that area as well! For example, we have dedicated Issue Triage Specialists which keep track and answer a lot of the newly created ones.