The other have is how it is used. Poor presenters will simply stand in front of a group and read their poorly-prepared slides. I have seen this so many times, I am turned off as soon as I see a PowerPoint slide. Of all the aging MS Office applications, PowerPoint is showing its age most of all.

Humans CAN make effective PowerPoint presentations, but it requires more work than drag-and-drop from a word processor or web browser.

I get better results using Keynote on a Mac. At a minimum, it forces the audience to think "Hey! This is NOT PowerPoint!". That only carries me for the first 30 seconds, but it gives me a window of opportunity to introduce my topic before the "PowerPoint siesta" begins.

For a collaborative discussion, ditch the presentations altogether and proceed to a smart board or a low-tech whiteboard.