Since I am an automation developer, I use selenium a lot. It is quite easy to run the tests in circleCI. Without using browserstack or saucelabs or xvfb, circleCI pre-installed chrome/chrome driver and firefox for you. It is quite good.
And it is fast to setup everything. My learning curve of circle is shorter than jenkins and teamcity.
save our money for buying plans of browserstack or sauce labs
save our time, do not need to setup our own xvfb, selenium grid or other stuff.
1. The feature of building CD pipeline as Jenkins: I confirmed with circleCI, this is in their to-do list
2. customized view of the pipeline and builds.
3. different triggers for the build, not only trigger by the github updates
4. If they can provide more examples in the documents? But I can find the examples in the discussion board anyway.
For half year we have used circleCI, then we go back to jenkins. Since the CD pipeline is very important to us. Our current solution is to install xvfb and firefox in the jenkins node.
CircleCI has their strength such as very easy to be used but jenkins are still very powerful, jenkins has so many useful plugins to help deployment.
And since AWS has the code pipeline and our company are moving to AWS, we are using Jenkins + AWS. So we totally got rid of CirclCI this year.
Since it was quite easy to set up the build/job in circleCI.
AWS provides more options with Jenkins. Jenkins has plugins to work with AWS. And they are able to achieve more complicated tasks. Such as triggers.