Updates are not so complex that they cannot be accomplished in a reasonable amount of time (usually weekend or late night weekdays if change control is approved). This keeps compliant with security updates to product as well.
Atlassian support is also great for all its offerings including Bamboo. However, we feel that Bamboo does not get as much love as some of their more popular offerings such as Jira and Confluence, and it sometimes takes a bit longer for issues and feature requests to get addressed in comparison.
Bamboo is a fairly small product but having said that it was fairly easy to get assistance. Especially for the small to easy things. Anything large or fairly complex was an issue finding detailed answers for. This caused a lot of trial and error on our part to try to find a solution.
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.