I currently use an SD card with 16GB Class 10 of the same make and I get (with H2testw)
Writing speed: 11.5 MByte / s
Reading speed: 39.1 MByte / s
reading it is like a conventional hard disk (not USB 3, but it's still a hard disk speed :-)
So I do not regret this purchase at all for the price of an SD card reader + this is comparable in price to speed as USB 3.0