Models and objects are limited to small groups. Good ones tend to be expensive, costly to duplicate, and often unwieldy. Models require ongoing narration from the speaker to come to life, but this need means that the presenter has flexibility and can change the speech to fit the audience. As with videos, models work best when the situation really calls for them.
When you pass out objects, samples, handouts, or other materials as visual aids, you lose attention as you do so. Don't introduce vital new points at that time; rather, use the time to summarize or to describe the object being distributed.