I'll elaborate a little.
Go get HDTach, and a good MicroSD adapter (cheapo ones and adapter cards are no good).
Then run tests on each MicroSD, making sure to reboot between them to clear the cache.
You'll discover that Sandisk is, CLEAR ACROSS THE BOARD, about 9-10MB/sec. reads. Every product, every size. It's really reliable stuff. Always the same.
Kingston Japan varies by size, but the 2GB sticks run about 18MB/sec., and the 1GB about 20MB/sec.
A-Data and Transcend are all over the place. Their Class6 stuff is USUALLY faster than SanDisk, but sometimes it's only 11MB/sec. and sometimes it's 18MB/sec. and you never know what it will be, it depends on the fab and the batch and place of manufacture, etc.
I can never find the link on here that had a nice chart of RAM batches and speeds, but I know I've seen it. And it's amazing how many people don't know about it.
But I will tell you - $6 from New Egg gets you a 2GB Kingston Japan, shipped, that I guarantee will run TWEWY.