Open Social positions its product of the same name as a “flexible Community Experience Platform” (CXP). The approach is divided into two parts. On the one hand, there are the core functions of Open Social, which is developed as an open source project under the responsibility of Open Social itself, with the support of the Drupal community and partners. On the other hand, Open Social offers additional “enterprise functions” for a fee. The great advantage of this solution approach is that individual functions/experiences for a specific customer request can be easily integrated into the community. We ourselves (crowd-creation GmbH) have been successfully using Open Social as a platform for market research communities for 6 years. We use the Open Source core functions and add individual functions/experiences developed by us. Review collected by and hosted on G2.com.

I can't point out any downsides of Open Social, which can't be solved based on the Open Source nature. Review collected by and hosted on G2.com.