I've always been very attached to my internal monologue. If I weren't, I don't suppose I'd have quite so much to say here. Internal monologue has some great advantages. For one thing, I can be certain my audience is interested and focused on everything I have to say. I can follow multiple paths at once, without risk of confusion. I can loop back through the same topics as often as needed, or skip ahead without warning. I can take myself as deep as I want into something as fast as possible, without making sure someone is following me and without concern over whether I'll inadvertently say something that will hurt, offend, or annoy someone else.
What the monologue tends to lack is new information. It's very easy to get stuck in a rut and repeat the same thought loop for long periods of time. And there is no feedback to catch false assumptions or faulty logic.
Dialogue, on the other hand, is interchange with an entirely different set of thought patterns and information. It provokes fresh thought in new directions. A good dialogue generally brings its own reward, as well - even the most anti-social human is still a social animal.
However, dialogue tends to be either slow or superficial. It's prone to misunderstandings and confusion of definitions. Once a conversation has moved on from a point, it's not likely to get back to it without a great deal of work, even if I have new thoughts on it, unless I'm talking to someone else who participates in circular conversations. This is especially true when I wasn't ready to move on.
One thing that is rapidly becoming one of my pet peeves is something that I'm every bit as guilty of as anyone else I talk to. That is "Let me think about it and get back to you" and variations on the theme. The way I use it, and others use it to me, generally means "I really ought to think about that right now and give you a useful answer, but I don't want to think about it, so I'm just going to quietly forget it." I am coming to dislike it greatly, and I want to break myself of that. Sadly, due to the quietly forgetting about it, I can't remember who and what I need to answer right now...