Just bought the Samsung T5 500GB SSD and ran some speed tests against the PS4 slim HDD. Not scientific by any means but got some some interesting results. See comment below. Btw
Seagate Gaming GAME DRIVE SSD 500GB Game Drive PS4/PS5 new sealed 763649171073 | eBay
The best PS4 SSD for 2023: Improve load times and boost your storage | GamesRadar+