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
Samsung T5 500GB,External, 2.5 inch (MU-PA500B/AM) Solid State Drive for sale online | eBay
Boxed Samsung T5 500 GB USB 3.1 Gen 2 External Portable SSD Drive (MU-PA500B) | eBay
SSD drive Samsung T5 500GB, blue (mu-pa500bww) box solid-state computer non-volatile non-mechanical device capacity component part storage chip hard disk