First of all, this is the fastest flash drive I've owned so far. Keep in mind, to receive the fastest transfer speeds, you WILL need to have a USB 3.0 port on your desktop or laptop. However, it transfers files beautifully even when plugged in to a USB 2.0 port.
This is probably not typical, but on my first major file transfer (several folders with video clips and other files amounting to about 13gb) I got speeds of 100mb/s which eventually slowed down to an average of 60mb/s. That's still a huge step up from the 2-5mb/s I would get with my old flash drive.
About the capless design, it is okay but not the greatest. It uses a spring-type mechanism similar to the capless pens where you "click" it to open or shut it. It's definitely not worth making a fuss about, and other than that little detail, I can recommend this flash drive without any hesitation.
This is a nice compact USB flash drive with good speed and quality. What can you say? It gets the job done. The size and design are nice. With large capacities it's so important to have USB 3.0 speeds if you're copying and retrieving a bunch of data all at once.
The Supersonic Xpress USB 3.0 flash drive brings the speed and performance of USB 3.0 at an affordable price. Featuring a stylish cap-less design that hides the USB 3.0 connector when not in use, the Supersonic Xpress works like a pen to reveal the USB connector. Transfer data in a flash with speeds up to 60MB/s read and 25MB/s write when connected to a USB 3.0 port. No USB 3.0 port? The Supersonic Xpress is backwards compatible to USB 2.0/1.1 and comes with a 2-year limited warranty.