I'm a blue-collar guy who is currently enrolled in a part-time MBA program that is designed for working adults, and the rest of them are white collar. Whenever the courses require PowerPoint, the slides flow freely and in dizzying density and volume.
I, on the other hand, gave the best presentation of my life without a single slide, and even when I need to use them, I limit myself to 3-5 slides. Working on team projects, I often need to talk down my colleagues who think that more slides = better presentation. One guy had 13 slides for a four minute presentation, other times people are trying to cram spreadsheets into slides and expecting the audience to be able to pick out some kind of useful information.
If it were up to me, I'd always do it without the slides. Once I master public speaking that way, I'll maybe consider using PowerPoint.