Great for MVP version, but requires some work
SocialEngine is Zend Framework based, which is good. However, server requirements are higher because of this. So you will need at least a good VPS for the hosting.
1. It's stable, and fully supports php7.
2. The most recent version uses LESS as css preprocessor.
3. There is a huge pool of plugins to choose from.
4. It's a perfect solution to try different project concepts.
1. Plugins quality varies.
2. UI might be better.
3. Zend Framework version isn't the recent one.