Transfer speed is as previously mentioned fine.
The big flaw in this product is supplied (for me indispensable) SD adapter which makes the card for use in digital cameras almost useless:
The lock-slide (write protect) is namely so loose that the card when inserted into a reader or digital camera is always locked. Accordingly one can not use the card as well.
Have an emergency solution a thin strip Tesa film about so stuck that the slide can not lock; but is of course not exactly brilliant.
CONCLUSION:
Who only the pure micro-SD requires => hui!
Who is dependent on the adapter => Pooh!