No USB-C, no encryption
Out of the box, the GT is preformatted in exFAT, allowing it to work with both Windows and Mac interchangeably without reformatting. But if you have one of the new MacBooks, you're out of luck -- unless you get a dongle -- since the drive doesn't have a USB-C port; instead it uses a regular USB connector. Kingston told me it might release a USB-C version in the future.
The drive also doesn't include any security features, so if you lose it, everyone will be able to pry into your data. Many thumb drives don't feature encryption, but most thumb drives have just around 10GB of storage space and cost less than $20. Two terabytes is a lot more data to leave unprotected.
The GT is indeed the fastest thumb drive on the market. Via USB 3.0 (also known as USB 3.1 Gen 1, which caps at 5 gigabits per second) it registered sustained copy speeds of 165 megabytes per second for writing and 327MBps for reading. While these aren't the fastest I've seen, the GT is among the top high-performance external drives on the market. And speed is important in this case. The GT is so large in capacity that even with its fast performance it still takes you some three and half hours to fill up the 2TB capacity.
The GT also works with older USB 2.0 ports but its copy speed will then be capped at around 35MBps.
Should I get it?
The Kingston DataTraveler Ultimate GT is more of a "big toe" drive than a thumb drive due to its bulky design, and the fact that it costs an arm and a leg.
That said, the drive is fast and, for now, unique due to its huge storage capacities. If you have a lot of cash and don't know what to do with it, the GT is worth considering. Otherwise, I don't see why you should pick this drive over the faster, more feature-rich Samsung T3 (or even the older version T1) that costs less than half the price for the same amount of storage.
If you're really intrigued by the GT, wait for the price to drop. Of course by then, competing drives with better features might also be available.