I've used GitHub Actions quite extensively now, across infrastructure automation, Python CI/CD, and iOS CI/CD, and while not perfect, it's the best platform I've used for this stuff so far.
Compared to Jenkins it needed far less maintenance. Compared to CircleCI it felt much easier to work with and to build reliable pipelines due to the locking primitives it provides, and compared to Semaphore I found it easier to understand how the pieces fit together.
My criticism would mostly be about missing features, but the pace of development has been great and the only one I have left on my list is SSH debugging, which didn't end up being much of a blocker to our adoption anyway.
As for reliability, nothing is perfect, but in my experience it's at-or-above the level that CircleCI provided, and far surpassed our in-house Jenkins server.
Compared to Jenkins it needed far less maintenance. Compared to CircleCI it felt much easier to work with and to build reliable pipelines due to the locking primitives it provides, and compared to Semaphore I found it easier to understand how the pieces fit together.
My criticism would mostly be about missing features, but the pace of development has been great and the only one I have left on my list is SSH debugging, which didn't end up being much of a blocker to our adoption anyway.
As for reliability, nothing is perfect, but in my experience it's at-or-above the level that CircleCI provided, and far surpassed our in-house Jenkins server.