the way it edits powerpoints is by launching a command line environment, and then editing the OOXML directly using command line tools. this takes several minutes to do even simple changes.

to me it seems miraculous that it even "sort of" works, but also it's not a reliable product yet. OOXML is very complex and the formatting can get mangled.

On the other hand, if you use LaTeX/Beamer slides, LLMs can reliably make a lot of formatting tweaks etc. and it is an actual time saver. But only weird academics use Beamer.

I agree with Simon Willison that this feature is really about writing code in a container, using that capability to edit PPT presentations as if they were markup is an odd thing to make the primary selling point.