While keeping meetings short has merit, if meetings are producing valuable content, then let them be long-er. From my own experience, I can share that product planning meetings by a collaborative team, where each member has been responsible for researching certain features, can be very productive. This allows team members to constructively challenge and add to the results. It’s also important to enter the meeting with a document having been circulated beforehand (for example, as a Google doc) so no time is wasted on unnecessary background discussion.