Good presenters weave speech, gestures, emotions, and--last but not least--visual props into a cohesive experience. If the slides are fundamental to your talk

Good presenters weave speech, gestures, emotions, and--last but not least--visual props into a cohesive experience. If the slides are fundamental to your talk you need to control the flow to avoid disruption. If they aren't, why do you have slides in the first place?