- Fast: I downloaded the latest CrystalMarkDisk 7.0.0 x64 from the CrystalMark.info web site. I tested the 32GB drive as it came out of the packaging, which comes formatted FAT32. As you can see from the numbers, it clocks average of 5 1GB reads at 155.18MB/sec. That's as fast as you will get from a mechanical hard drive. Writes are 46.77. That is good for a flash drive.- Small: It is almost exactly the size of a AAA battery (triple) except it is thinner. It will be smaller than a normal house key and way smaller than a car key. It's only the length of the USB-C metal end longer than my Kingston 8GB that I have had for years and has been through the war.- OTG: The biggest drawback of my Kingston is no USB-C, which means I need to have an OTG cable available to share it with my phone or someone with a MAC. I plugged it in and it was instantly recognized by my Note 9.- Keychain: I was concerned that the slot might not be large enough for the coupler of my keychain to slide through. There was plenty of room for it and plenty loose on the cable.- 32GB: Looking at benchmarks around the web, I detected a pattern between capacity and speed of USB Flash drives of the same base model, depending on the technology they use. Sometimes the larger capacity ones are faster and sometimes the lower capacity ones are faster. With the SanDisk Ultra Dual Drive Go USB Type-C Flash Drive - SDDDC3 and its close sibling SanDisk Ultra Dual Drive USB Type-C - USB-C, USB 3.1 - SDDDC2, the pattern appears to be the-smaller-the-faster. My test confirms that as well. Bigger is not better for other reasons as well. 32GB is the largest you can go and use the FAT32 format. The FAT32 format can be read by pretty much anything. Also, if you want it to be bootable, FAT32 can be used to boot computers set up secure boot and UEFI and BIOS, without reconfiguring the computer and losing visibility to the computer's hard drive. If you see yourself using it for all of these things, then FAT32 and 32GB max is the only way you can do all of these things from a single USB drive. You will hear people say that with Windows 10, you can partition it and have a FAT32 partition. That's true, but then only Windows 10 and UEFI can read it, and if you use it to boot with, it will be astoundingly slow, and that's the case even if you make a 32GB FAT32 partition on lightning speed SSD, let along a flash drive.- Temperature: People talk about heat, but I checked it with my heat gun which is very accurate. It went from 71F to 72F and back down to 71F. Then I noticed that the closer to the laptop I measured the warmer. I discovered the port area on the laptop was 77F, so I don't know if it heats up measurably at all.- Durability: The jury is still out as to how well it will hold up on my key chain. My metal Kingston has a nasty dent in the NARROW side on the corner, which would had to have taken quite a hit somehow to produce. There seems to be enough plastic where the key chain goes through the holder. The flash drive swivel could be a failure point, however the natural tendency would be for it to streamline within the holder. The area of most concern is the rectangle plug-in of the USB-A end, which is like a vinyl plastic, unlike the metal USB-C end. However, as of this update on 7 weeks later, it's holding up just fine.