We are moderately happy with ActiveCampaign. We are attempting to not use Salesforce or Hubspot to keep costs in check so we expected to lose some functionality - AC is better at Marketing Automation than CRM (by a lot).
After years of using Teams and Slack, I can't go back to Teams, ever. Slack is a great tool but can become unwieldy if processes are not place for managing channel bloat. Having some thoughtful rules around archiving and when to use is great but it's a must have for remote teams.
Readme was very easy to build into our website for product docs, api docs and our changelog. We would have loved a bit more customization options for look and feel but it's a great product overall.