I've always preferred the format where the speaker or moderator asks for several questions in one round, then the speaker can pick off each question in one go.
This approach puts the onus on the questioner to be as concise as possible, which is not too much to ask in consideration of the audience.
It becomes more difficult to grandstand when the audience recognizes that the objective is to collect a set of questions as quickly as possible and you taking 5 minutes to set your question up is at best tedious and at worst insulting to everyone in attendance.
One good trick is to ask people to make their questions as short as possible.
One speaker asked to use up to 8 words per question (and he actually counted the words and rejected the long questions;)
Another speaker had a list of pre-submitted questions, and he deliberately ignored long questions, and only answered the short ones.