Concourse looks very promising and the UI is impressive. Before evaluating it, I was glad to discover the "versus" page as I am a Jenkins user (and I guess other people as well).

The page at https://concourse.ci/concourse-vs.html has obsolete/wrong information.

First bullet point - Jenkins servers become snowflakes

This was true for Jenkins 1 but no longer holds for Jenkins 2. Jenkins 2 has Jenkinsfiles (same thing as Travis mentioned later in the same page). Nothing is defined in those little textboxes anymore. These files are pushed to version control so bringing back a Jenkins server is a trivial task.

Second bullet point - Pipelines as first class concept

At first glance Jenkins 2 might indeed seem like Jenkins 1 plus the pipeline plugin. This could not be further from the truth. Jenkins 2 is a completely new platform. Pipelines are now a first class citizen and they are defined in either a declarative way (as Travis and Concourse do) or in a programmatic manner using Groovy and all its power.

Third bullet point - Everything in Jenkins requires plugins

Again this used to be true for Jenkins 1 but not true in Jenkins 2. Given the power of Groovy (i.e. having a full programing language) means that you can do whatever you want on a pipeline without the use of other plugins. In 99% of the cases apart from the basic plugins (i.e git and maven) no other plugin is required anymore.

Fourth bullet point - "Finding output logs takes 3 clicks"

This is the point that actually forced me to open this issue. Whenever a build fails in Jenkins, you get an email, you click on it and you go directly to the failed output log. It doesn't get any simpler than this.