I copy an ISO file on it from my Mac to Mac Journaled format, to compare it to a USB drive Corsair Flash Voyager 16GB:
Iso file of 692 MB: Samsung 16GB SD copy in 1: 21mn
Corsair Flash Voyager 16GB USB key 1:26
All this to tell you that this Micro SD Samsung is really successful and for the price of 6 euros for 16GB not hesitate.
Now you just need to know if it is solid and only time will tell, in any case one thing is, it's been 6 years since I have my Corsair USB key and it still works perfectly.