Super easy to install and maintain.
The UI is really clean and it makes really easy to visualise where you are in the pipeline.
Also, the ability to extract templates from existing pipelines makes super-easy the addition of new projects.
The setup was a little bit crafty: first we had to understand how the general view of the product (environments, builds, tasks), then we had to write some ad hoc scripts to achieve what we wanted. It would be nice to have some built-in templates for the most common type of applications -- as far as I am aware there aren't any at the moment.
Also, the concept of environment didn't really fit the need of our team: we ended up using only one environment. Our pipeline was looking something like the following:
build > test > publish > deploy-to-staging > testing-on-staging > (manual sign off) > deployment-to-prd
Because of the structure of our pipeline, we could not manage to lock our pipeline as it was completing only when deploying to prd -- and obviously this wasn't happening for every candidate that was released.
This caused us some headaches when 2 pipelines of the same project were building at the same time.
We had the need of releasing frequently and quickly.
We wanted to automate the test and release process as much as possible so that this was not time consuming for the dev team.
Also, we wanted an infrastructure that a team of non-dev-ops could easily maintain.