Massive Open Online Courses based on the principles of connectivist educational pedagogy known as connectivist MOOCs (c-MOOCs) have been carried out with great success during the last years with hundreds of registered participants. Examples are CCK08 (2008), PLENK2010 (2010), MobiMOOC (2011), EduMOOC (2011), Change11 (2011/12), and LAK12 (2012). Their implementation required conceptual changes in perspective from both "facilitators" (tutors) and learners. They are so novel that much research needs to be done for their understanding and improvement. Basically two very distinct delivery formats have been used: (1) Those that use what's referred to as an aggregator, an emailed daily newsletter, called "The Daily" that captures contributions from tutors and participants mainly from their blogs: Format A; and (2) Those where all events go through a "centralizing" web page or wiki and discussions happen with the use of a mailing list, in most cases using Google Groups: Format B. In this paper we study in detail representative courses. From their comparison we establish that connectivist MOOCs delivered with formats A and B share many common features but that their differences are such that the learner's experience and the outcome of the courses are very different depending on the format used. (Contains 2 figures and 1 table.)