С. Animation. Animation and transition schemes are not the same for PowerPoint and Google Slides. So just check the presentation on the preview. In my experience, often it worths it to delete all animation and start from the very beginning if you used Morphius effects etc.
D. Charts. Charts that were created in PowerPoint will be not converted to charts in Google Slides. Instead, they will be pictures, actually pictures not in good shape - they might be stretched, placed in the wrong place etc. This is the weakest point for business presentation but it works only in this way right now.
E. Smart Art. Mostly good after converting. It converts like a group of shape, which are editable in Google Slides. But you can't add a new element. Like if you have 3 columns of Process Smart Art it will be not possible to add automatically 4th column, only copy paste and align 4 columns once again.
F. Video and audio. The scheme to work with video and audio formats is different for PowerPoint and Google Slides. But I have admit great benefit of Google Slides - if in PowerPoint you limited with size of files which can be added to presentation, as it is affect to the size of ppt file, Google Slides allow to add as much videos as you need and presentation will work good, without any issues. It is very comfortable.
G. Right place for every detail. Overall, while converting some elements can be moved (a little bit or a lot). So better to review slides in Presentation mode, and check that everything looks good.
And here is the summary from the business presentation designer: It is very easy as a process, but you need to spend some time to check slide per slide carefully and fix some issues which might appear.