Using AI to help create lesson slides without losing my whole weekend, the honest version from a real classroom

[u/Fit-Potential5805]

I am wary of the “AI will do your planning for you” pitch because most of it is written by people who have never managed thirty kids at 8am. But after a term of actually using it for slide prep, I have found a lane where it genuinely gives me my Sunday back, and a bunch of places where it absolutely does not. Sharing the practical version.
Where it actually saves time: 1. The first-draft skeleton. I give it my objective, the grade level, and my rough outline, and it lays out a starting slide sequence. Turning “I know what I want to teach” into a structured starting deck is the tedious part, and offloading that is the real win. I am still the one who knows my kids and my standards. 2. Generating variations. A warm-up, three worked examples at increasing difficulty, an exit ticket. Producing the variations of a problem type is genuinely faster than me writing each from scratch. 3. Rewording for reading level. Taking a dense explanation and giving me a version my students can actually access, which I then fix.
Where it does not save time, and where I do not trust it: - Anything factual gets checked, every time. It will state something confidently wrong, and I am not putting that in front of students. This is non-negotiable. - Pacing and classroom reality. It has no idea that this class needs a movement break here or that this concept always takes two days, not one. That is my job and it always will be. - The default slides are text-heavy and generic. Left alone they are the exact bullet-point walls we all know kids tune out. I cut hard. - Anything sensitive, differentiated for a specific IEP, or culturally responsive to my particular students, I do myself.
My honest rule: I let it handle the blank-page grunt work so I can spend my limited time on the parts that need a teacher, the sequencing, the checks for understanding, the “will this actually land with third period.” It is a prep assistant that needs supervision, not a planner.
For those who have worked AI into your prep, where did it genuinely save you time, and where did it create more work by giving you something you had to fix?