Those impressive speeds should let you edit RAW 4K video, for instance. On top of that, Samsung is offering the T5 with some pretty high capacities: 250GB, 500GB, 1TB and 2TB. While it won't hold as much data as mechanical disks, the 540 MB/s speed is nearly five times as high, and you'll also get better longevity, reliability and ruggedness than a hard disk.
What's more, the T5 is just 3.0 x 2.3 x 0.4 inches high, weights 51 grams (1.8 ounces), supports 256-bit hardware encryption and comes with a smartphone app. Samsung has even thrown in a couple of cables, a USB-C to C and USB-C to A, making it easy to connect to just about any device. (You'll need a PC with USB 3.1 gen 2 tech, capable of up to 10Gbps to get the full 540 MB/s data rate, Samsung says -- and even then, you'll probably see speeds below that.)
The rub, of course, is the price. The T5 is not aimed at the backup crowd (unless they need to do it really quickly), but rather multimedia users who need high sustained throughput speeds. As such, the 250GB T5 runs $130, more than you'd pay for a 3TB portable mechanical disk on Amazon. The 1TB model runs $400, while the high-end 2TB models is $800 -- at least six times the price of a comparable mechanical model.