In my own attempts to study philosophy, I've found classical monologue-based instruction almost invariably suffers in comparison to dialogues between multiple people genuinely trying to convince each other of their ideas. When the author cannot interact with and respond to their audience, it's easy to become complacent. Dialogue forces one to refine both one's ideas and the presentation of one's ideas, and makes it much easier to realistically compare a point of view to the most compelling alternatives.

Definitely true. Might I add that forums/blogs are better than real life (verbal) discussions for developing insightful ideas, precisely because you must put in more time to develop a forum/blog post (and also because there are no distracting non-verbal stimuli that may make someone look "smarter" or more "authoritative" than someone else - so only the best ideas get selected, rather than the ideas from the most respected/most prestigious person), and also because it's much easier to refute individual (quoted) points that way.

Furthermore, people will forget points communicated verbally. Points communicated through forums/blogs will stay for a long time, where someone can search for them (and think about them) months later.