When reading a USB 3.0 Card Reader Transcend 300x 32Gb card is slightly faster than the SanDisk Ultra 32GB Class 10 with 32GB. The Transcend 600x is again a little faster when reading - allderings hardly noticeable.
So far I have no problems with the card.
Price / performance ratio was just - my conclusion: there must be no specialist Transcend 600x. This is enough perfectly.