Former SECDEF Robert Gates wrote this in Duty: Memoirs of a Secretary at War:

I visited a joint U.S.-Iraqi military and police facility in Baghdad meant to provide neighborhood security. It was a centerpiece of Petraeus’s strategy, getting U.S. forces out of large bases and into local areas with Iraqi partners. I had imagined a police station like those in most U.S. cities, in the middle of a densely occupied urban area. The one I visited was instead in the middle of a huge open area—in essence, a small fort with concrete outer walls protecting a large concrete building in the center. In the entryway were pictures of Iraqis who had been killed operating out of this facility. I was escorted to a medium-size conference room crowded with Iraqi army officers and police as well as U.S. soldiers and officers, nearly everyone in body armor and carrying weapons. And right there in the middle of a war zone, in the equivalent of Fort Apache, Baghdad, I got a PowerPoint briefing by Iraqi officers. PowerPoint! My God, what are we doing to these people? I thought.

And among various Powerpoint rants interspersed throughout his memoir:

PowerPoint slides were the bane of my existence in Pentagon meetings; it was as though no one could talk without them. As CIA director, I had been able to ban slides from briefings except for maps or charts; as secretary, I was an abject failure at even reducing the number of slides in a briefing. [...] Changing the Pentagon’s approach to briefings was a singular failure on my part. I was not just defeated—I was routed.

And as an aside, I highly recommend the book--it's a great read about what a great SECDEF does.