Schoology is a full featured, robust platform in its own right, and many, many schools use it as the only tool for student communications. Though it would be simpler, less expensive, and much easier to deploy, our CA approach (perhaps unsurprisingly) is to find the best tool for each use-case scenario that we are trying to solve for.
The most popular and powerful email platform right now is Gmail, the most widely-used Group communication tools are vBulletin Forums and Google Groups. We are making choices that prepare our students for their future (and current) work requirements. For the most part, if we are using an educational tool, it is because it is tailor-made for the specific use. Schoology has an incredibly rich and feature-filled tool set around assignments (giving and returning). It's Group messaging, peer-to-peer messaging, and resource-sharing functions are not as advanced, so we aren't using them.
We will be using Google Calendar for internal events, Trumba for events publishing, ScheduleOnce for meeting scheduling, and Schoology for assignment scheduling. More than likely, as interns, CA students will be better equipped to demonstrate and develop business scheduling processes than the employees working there. Simply, that is the goal.