I just received mine - for what it is worth, when tested using a card reader attached to a USB port on my laptop, I am getting close to class 6 write speeds, ~5.8MB/s. For reference, my 16GB class 6 Transcend card tested at ~9.2MB/s. In terms of read speed, my SandDisk 32GB class 2 is showing ~13.7MB/s while the Transcend is clocking in at ~15.7MB/s.

So obviously, the Class 6 has faster write speeds, but not so much faster than what the difference between a Class 2 and Class 6 should predict.