It generally depends upon the topic and I guess the level of detail we are looking for from the presenters.
It has been my experience that just about every presenter who comes before the committee will use up the ten minutes--and then some. So it might not be a bad idea to limit the number of presenters per meeting. That's not a bad idea at all, because we could take up a large part of the meeting just for presentations, and a lot of members would have questions that they wouldn't get to ask if we run out of rounds.