Use of modules to allow for customized code and the ability to maintain virto core with updates.

Like all the features and especially the catalog store and the easy-to-use eCommerce parts.

I very much like how solid the platform is and how well-structured the APIs are. Virto's APIs are well documented and provide the majority of functionality that we need to build our implementations. Also, I like how easy it is to extend the platform and that the methods of extending the platform do not hinder the upgrade path for our implementations. Virto's support also has been very quick and knowledgeable.