Tested every 10 hard drives (5 colors), 8 stable tested at 9 - 12 Mbit/s (USB 2). Ironically, of the 2 black drives, one tested consistently higher (11-18Mbps) and the other black drive significantly lower (0kb - 17kb - 100kb - 4mb). So, not sure what's going on there, but generally good enough for my purposes. I haven't had them long enough to determine durability and as the speed of the 2 black discs varies significantly I'm unsure on quality control. (I would probably give 5 stars if the 2 black disks matched the rest better.)
Samsung BAR Plus 128GB USB 3.1 Flash Drive - 400MB/s - Champagne Silver (MUF-128BE3/AM)
65 Review
Kingston DataTraveler flash drive 100 G3 256 GB, 1 pc. black
74 Review
Titan Gray Samsung BAR Plus 256GB USB 3.1 Flash Drive (MUF-256BE4/AM) with Up to 400MB/s Transfer Speed
69 Review
Kingston DataTraveler SE9 32GB USB 2.0 Flash Drive for Reliable Data Storage (DTSE9H/32GBZ)
69 Review
π Seagate Expansion 3TB Portable USB 3.0 External Hard Drive (STEA3000400) in Black
60 Review
2 TB External HDD Western Digital WD Elements Portable (WDBU), USB 3.0, black
84 Review
18 TB External HDD Western Digital WD Elements Desktop, USB 3.0, black
95 Review
Game console Microsoft Xbox One X 1000 GB HDD, black
53 Review