There were no particular stability issues. Alfresco underwent a major refactoring in a few areas of the product, such as:

• Migration from ANT to Maven building environment
• Migration to Solr first, and Solr4 eventually
• Introduction of Dojo JS framework
• Angular2JS

These changes require engineers to pay particular attention when migrating or upgrading older versions of the product. As long as they follow the recommended upgrade procedure, there wouldn't be any major issues.

Alfresco has a very steep learning curve, and unfortunately, during the learning process, it's very easy to make errors, which often are unforgiving.

This is also why usually companies interested in buying Alfresco have to rely on companies that are specialized in administrating and customizing the software.

No, but as said in previous question, Alfresco requires an experienced certified administrator to install it properly in production.

We did encounter some stability issues when there were many simultaneous requests on the server. At such a time, the server may go down but actually we avoided this by setting up JVM parameters.

No issues with stability at this time..

We did not encounter any stability issues; only some minor improvements are needed.

I have not encountered stability issues.

For large repository sets, the architecture must be well sized.