Mesos is really great when you have a big datacenter with many different applications and use cases. It will help you to optimize the resource usage, being a centralized API for your infrastructure. It will not suit well for small companies that just need to deploy a web app. In this case, I would recommend something smaller.
Mesos may have many frameworks. If you have Mesos installed on your servers, you may use it for many kinds of tasks. Today we're running only web applications but the idea is to install a different framework for big data soon.
Unreliable deployments that would fail for no good reason. Sometimes our Docker container would be "restarting" forever because Mesos thought it didn't have enough resources to start the container.
Impossibly slow UI. Built in React under the hood with a lot of bloatware backed in, so loading the Mesos UI on a slow internet connection was painful.
No real logging solution - it would stream "console.log()" output to the UI, but searching for logs wasn't really possible without downloading a huge file.
No built-in support for redeploying containers from a CI. We had to create a service whose whole job was to expose an HTTP endpoint that restarted a container, and then made Circle CI ping the endpoint whenever we wanted to redeploy.
Kubernetes is by far the best choice. More reliable and better developer experience. Mesos is prone to sporadic failures and not really designed to handle CI/CD-based deployments. Docker Cloud once shut down our entire cluster for "upgrades" without giving us any warning.
