It's Open Source, free, with a massive database of plugins for free, works out of the box, and includes practically everything you'll need to start your online store. It is maintained regularly, and the forum is a great source of information and to get help. Review collected by and hosted on G2.com.

There's not much integration with new apps in the market, so it's difficult if you want to sync or connect to those apps. Lack of good free templates. Some modules should have been integrated with the core code years ago, but they still not doing it (even with some plugins that were developed by a team member of ZC). Review collected by and hosted on G2.com.