For me, I made sure I had the latest/recommended USB 3.0 188.8.131.52 driver installed for my tZilla laptop from here, then simply downloaded the free benchmark utility from:
which takes only a few minutes to run (no install necessary, just extract the 3 files and launch the exe). It even auto-uploads the results. ATTO Benchmarks I got were similar, but this was so much easier to publish. Not the most scientific or trustworthy results, since you don't know what USB controller, firmware, and driver were used for the tests, or if the drive was freshly formatted and healty. But it's still a good way to get some idea if the results roughly match the states specs on Amazon or NewEgg.
Now I know which of these 3 drives I had laying around that I'll be using for my Windows 8 RTM installation tomorrow (even in a USB 2.0 port, those USB 3.0 devices that score highest here will fare better during the intense reads during OS installs).
1) Transcend JetFlash 8GB USB 3.0 Flash Drive Model TS8GJF700
2) Team Color Turn 8GB USB 3.0 Flash Drive (Purple) Model TG008GE902V3
I saved the best one I have tested for last, Read is 79.04MB/s, Write is 44.65MB/s:
3) ADATA N005 Pro 32GB** USB 3.0 Flash Drive (Gray) Model AN005P-32G-CGY
Yeah, it's big, it's ugly, but it's also fast!
Feb. 04, 2013 Update:
Ah, progress. Speed goes up, price falls down.
4) Ventura Plus Series USB 3.0 Flash Drive 16GB
There's certainly cheaper USB 3.0 flash drives these days, seen on Newegg and Amazon. But for what you loose in write speed and cost with the Mushkin, you gain in read speed. If booting recovery media is your goal, then this fits the bill, since that's mostly reads. My testing was done with a Lenovo W520 Laptop's USB 3.0 port, using Windows 8's built-in drivers.
You'll see my 16GB drive testshere:
then head on over the main leaderboard here:
and apparently this little drive isn't the only Mushkin up there today, but it's the fastest: