If you consider ProRes to be an All-I version which I think it technically is, then Mac computers (and many others) have hardware support built in so processing that is very, very smooth. For whatever reason, both Mac and PC users are reporting...
my brother would convert all his files to ProRes before editing but he has a slow apple computer. He flew the Phantom 4 Pro. Well they better fix the All-I or that would be a reason to return it.