Adding text to a screen in a multimedia presentation that is identical to the narration harms the ability of the audience to understand the information. Removing the text increases retention, or the ability to remember the information, by 28%. Even more significantly, removing the text increases transfer, or the ability to apply the information, by 79%.
Powerpoint is not evil, it is only a tool and it has been abused.
It comes down to this. You are the presentation not Powerpoint. Powerpoint, like any other piece of technology, is a good slave but a lousy master.
You're in charge let Powerpoint support what YOU have to say, don't think it will help you if you don't have anything to say it just make it worse.