It's hard to review a product as seemingly simple as a USB Flash Drive, but I'll have a go...
I bought this Kingston Technology 8GB USB 2.0 Flash Drive because I wanted a Flash Drive to use with my Apple Aluminium Keyboard. If you're familiar with this keyboard you'll know it has 2 USB 2.0 ports, which is great. The problem is, the keyboard is so flat that clearance is very tight. So a poorly designed, chunky Flash Drive is unlikely to fit into it. Fortunately, this Kingston Flash Drive is so compact that it fits perfectly into either of the 2 ports on the Apple Aluminium Keyboard, and sticks out of the side by just 3cm.
Another reason why I bought this Flash Drive was for its design. It looks simple and smart. Some other Flash Drives are overly fussy with horrid colour schemes. This Flash Drive is just white and black, which, again, looks great with the Apple Aluminium Keyboard.
What repelled me from buying a SanDisk Flash Drive is their obsession with bundling software on them. I mean, who buys a Flash Drive for its software? To me, that's nuts. Honestly, whose idea was that? That's like buying blank DVD-Rs with software pre-installed on them, to "help" you. No thanks.
If I want software installed on my Flash Drive, I'll do it myself. And this is where having a Mac comes in handy. You don't need to install software the old-fashioned Windows way. You can just drag-and-drop entire Applications on to something like this Flash Drive, and run them off it. So for example, you could download Google Earth, drag its single icon to your Flash Drive, and that's it, you're done. You've "installed" a piece of software, not on your computer's internal Hard Drive, but on this tiny external Flash Drive. Plug it into any Mac you want, and you can run your Application straight off it.
Ok, what about performance? I haven't got a hugely scientific way of testing the speed of this Flash Drive. But what I can tell you is, I can open and play a 1280 x 544 H.264 movie trailer off it, instantly. Absolutely no delay. And I can scrub back and forth through the video file, while it's playing, all in real-time. No loading, no waiting. So, as far as I'm concerned, the performance is great.