I am not familiar with the kirkwoods that you mentioned.
Just to be clear, the USB drive I was describing is rotating media in an external enclosure, not a memory stick. Generally self powered, as powering a portable hard drive from USB with a RPi is asking for trouble.
I have stopped buying flash memory devices from eBay and other vendors that are not well known with a reputation to protect - far to many counterfeits with less storage than the packaging claims on the market, and if you are unfortunate enough to try using them with the FAT or eFAT filesystem they are supplied with, data will eventually wrap around and destroy itself, probably after sufficient time that the seller (who may well be ignorant of why his/her stock was so cheap) is no longer around to complain to. A minor annoyance for me, but must be a lot of unhappy people losing irreplaceable photographs.. Fortunately for me, attempting for reformat with a Linux filesystem tends to fail on such devices, so I find out straight away and get to send them back and be refunded . I had to write a dedicated test program to demonstrate the subterfuge on the original filesystem - to prove that the reformatting was revealing an issue, not the source of it (as was often claimed).
I also don't buy cheap USB stick.
I like these
because they have a real hardware write protect capability. Indispensable if you are going to be inserting them into other people's machines, but surprisingly uncommon.
At over $200.00 for 256GB, they are are a bit upmarket, but I havn't had any problem with them yet.
Anyway, so long as you are aware of the risks and limitations, flash memory devices are a useful technology, but not a complete replacement for rotating magnetic storage.