I've also seen it done very well.
My History professor, the power points are brief talking points. It's the stuff a good professor would have on index cards in the days before power point. Well, what most would have as the title for the index card. They help keep the lectures and peoples notes organized, but do not come close to substituting for either. If you expect to pass by copying and studying the power points, you'll fail hard.
The lesson is presented in the lecture. If he needs to present any substantial information visually, he'll go to the whiteboard, though he does often put useful charts up on the power point, and has used his image choices as starting points for class discussion. His lessons are better with the power points, but there was one time in his Western Civ class where he left his flash drive at home. He went on and presented the lecture pretty much as he would any other day, we just didn't have convenient headers for different sections of our notes that day.
I'm really impressed with how he handles Power Point. It is a tool that definitely improves his ability to teach the class, but he uses other tools as well in a well integrated way. And he can function pretty well without it should he need to. The tool is strictly subordinate to the goal. This makes it both more useful and less necesary.
Most others though, they try to cram all the material in the power point and read it nearly verbatim. I have trouble seeing the point in even attending class, just download the power points and read them myself.