I think it depends on the content. Stuff like briefings and essential character stuff, like the Ground Zeroes briefing, probably shouldn't just be tapes. And the codec was comfy.
At the same time, I hate that you can only access various conversations in certain rooms. I don't want to call Otacon 15 times for his 15 different lectures on how Metal Gear Ray works during the Ray battle in MGS2. I'd rather listen to that stuff at my own liesure beforehand.