Learning Circle is a learning platform designed for communities of civic-minded learners. We present Learning Circle and its evaluation. The platform-based course is compared to a course organised using the same structure but with a loosely-coupled media approach. We base our analysis on a sample of 126 active learners and 32 mentors across 2 courses (from more than 70 different countries). The contribution of this paper is the analysis of trade-offs for using a central custom platform vs. loosely-coupled resources in online learning. The main trade-offs we identified fall within two broad outcome categories: cognitive and social.