I have had the same Kingston DataTraveller DTSE9 since around 2010, when I was still in school. I've carried it on my keychain for at least 12 years and it still works, its "the old reliable".
That said, it's slow. Very slow. I use it mostly as a boot USB for Linux / Windows, so I need several sticks with decent random read speed, and decent write speed for when I update them.
My criteria were:
All-metal construction for durability, including the keychain loop
Sits well on a keychain next to keys
Reasonable speed, including random reads.
Testing method
I evaluated the sticks in two ways.
I ran CrystalDiskMark with 256 MiB (x5) configuration.
I also measured the angle at which the USB stick sits on a keyring. I found that several of them could not sit perpendicular to a keyring it because of their geometry, which makes it difficult to comfortably use them next to keys.
At the datum of 0 degrees, the key sits perpendicular to the keyring.
Results
The competitors
Here are the 6 main competitors in this space I bought.
All transfer units are in MB/s.
Product
Price (£)
Angle on keyring (0deg is best)
Sequential reads Q8T1
Sequential reads Q1T1
Random reads Q32T1
Random reads Q1T1
Sequential writes Q8T1
Sequential writes Q1T1
Random writes Q32T1
Random writes Q1T1
Corsair GTX 128GB
65 (256GB version)
0
470.214
429.330
157.436
19.390
436.990
414.201
166.829
38.937
Samsung Bar 64GB
10
55
305.424
305.268
14.517
13.428
36.434
36.247
20.537
21.619
Kingston DTSE9G3 64GB
11
0
246.705
244.496
13.756
13.028
100.236
110.054
0.484
0.474
Integral Arc 3
10
0
162.336
161.338
15.567
11.188
49.457
47.965
5.032
4.244
Kingston DataTraveller Micro 64GB
11
0
247.000
245.247
13.788
12.961
100.932
101.292
0.496
0.470
Sandisk Ultra Luxe 64GB
12
25
403.863
399.974
12.438
12.054
91.835
91.685
4.272
4.258
Some additional notes:
The Samsung Bar had really sharp corners. You might need to file them down like I did.
Corsair GTX: the 128GB version is no longer available and the lowest capacity is 256GB. It's more of a portable SSD in the form of a USB stick, which makes it really fast, but it's bulkier than a normal USB stick, though not by much. Often it takes up more than one USB port because it's wide. It's still very good and I recommend it.
Other devices
Some related products I own but don't qualify for this comparison but are offered up here for context.
Here's why they don't qualify.
Crucial P3 Plus: It's an NVME SSD. Can be made portable with a good enclosure, but too bulky for what I'm looking for.
Samsung 860 Evo: It's a SATA SSD, definitely not the right form factor.
Sandisk Ultra Curve: I bought this thinking it was made out of metal, but it was not. It's fairly flimsy plastic.
Kingston DTSE9 16GB: This is my old stick. The old reliable. No longer sold, but I've tested its successor.
Samsung SD Card: It's a 2016 MicroSD card connected to my PC via a MicroSD-SD adapter and a USB card reader. I included this as a meme.
Product
Sequential reads Q8T1
Sequential reads Q1T1
Random reads Q32T1
Random reads Q1T1
Sequential writes Q8T1
Sequential writes Q1T1
Random writes Q32T1
Random writes Q1T1
Crucial P3 Plus M.2 NVME 2TB
1598.227
1332.131
305.220
46.643
1560.989
1452.256
238.134
102.502
Samsung 860 Evo SATA 1TB
564.446
539.913
272.631
43.322
536.440
518.168
238.752
101.313
Sandisk Ultra Curve
160.091
158.859
9.271
9.043
58.680
60.377
2.902
3.209
Old Kingston DTSE9 16GB
18.452
18.220
8.473
8.096
13.626
13.629
0.115
0.026
Samsung Memory Pro Plus Micro SD Card
20.765
20.969
5.146
5.102
19.493
20.316
2.181
3.421
Conclusion
There are no clear winners in this fight.
The Corsair GTX is the fastest in all categories by a country mile, but has a larger form-factor than other entries and higher price. Very good, but not for everyone.
Samsung Bar has the fastest random writes, and decent performance in other metrics for its USB stick form factor, but sits awful on a keychain due to the angled hole.
The Integral Arc 3 has solid random performance, but worst sequential performance than the rest.
Sandisk Ultra Luxe gets the best overall balance of performance, but does not sit on the keychain super well.
The two Kingston's perform effectively the same, with the Micro being much more compact. That said, that can be a disadvantage on a keyring if there are adjacent items.
All competitors (bar the GTX) had similar random reads.
For me, I'd say the right choice is either the Kingston DTSE9G3. It's a nice upgrade over my old DTSE9 and sits nicely next to it's grandfather. If I needed any random writes though, for copying lots of small documents like code files, I'd pick the Integral Arc 3.
you should check out the kingston SE9 G2. It has a smaller loop end and so it works way better on a keychain. unfortunately they didn't keep the feature for the G3.