For companies that are already using other Atlassian systems, then Atlassian Crowd will fit in very well. This is especially the case if the company is not yet big enough to use LDAP for user management, Atlassian Crowd can act as a temporary solution until the company outgrows it, as it is much easier and simpler than LDAP.
If you value integration over cost, Bamboo is clearly the way to go. It offers tight integration to the rest of the Atlassian suite, and when you need traceability from issue to build, Atlassian is the right way to go. However, if you find yourself needing to save on costs, you may consider taking an approach of rolling your own build system with open source alternatives, such as Jenkins, if you don't [mind] putting in a little extra elbow grease.
Levels of granularity. Organization has many projects that have many build plans that have many jobs that have many tasks, etc. And branch builds allow source control branches to be built separately.
Versatility. I can use bamboo to manage my Java, node, or .NET build plans. I can use it to spin up Windows or Linux build agents, or install it on a Mac to build there as well.
Bamboo integrates with other Atlassian products like Bitbucket, Stash, JIRA, etc. If a company commits to the entire Atlassian stack then work can be tracked through the whole development lifecycle which is really useful.
Bamboo was fairly easy to navigate but in the end it always felt as if it was developed as a bolt-on and not a true group up user interface. There were multiple ways to get to everything and the path was never the same. So it was difficult for users to really get a feel of how to use the application.
Overall, support is good, you get quick responses from Atlassian's official support system, and documentation is decent enough for you to find what you need.
Support for Bamboo has started lack a little over the years. Atlassian has been moving more towards Bitbucket Pipelines and away from the on-premise install of Bamboo. While the tool is still great, it may take a little bit of time to get a question answered by official support.
These products allow you to install them on your own infrastructure, so you can manage all aspects of them which can prevent you from getting throttled from API calls. When you hit a certain threshold of scale you may need to switch off of Atlassian Cloud to your own hardware. When you are a small startup, however, this product is probably a good starting point.
We selected Bamboo because its capabilities to integrate with other Atlassian products specially Jira Software, Bitbucket and in some useful scenarios with Confluence. Also, we found these pros important for us: great user interface, easily agent deployment, Docker compability, simply to maintain / manage, and straightforwardly integration with different notification platforms
New systems are tough when it comes to an ROI, as a dollar amount for saving time on a sign-in can be tough to track. Like most new systems that makes things slightly easier to execute as an end user or manage or support, it really might come down to the existing structure of how a company manages its users.
The positives are always with the end user, which I have to say, Crowd was able to accomplish.
It helped us achieve the Continuous Deployment and Continuous Integration goals for our applications, a huge milestone that saved a lot of time for developers in making the builds and deployments and saved time for QA in running the automated tests.
Helped with DevOps: we moved the formal approval from the email to the system and allowed the approver to actually push the button for the production deployments.
Biggest positive impact of using Bamboo is that it improved our response time to customers and increased the frequency of our deliveries to them.