Any need for USB 3.0 SD card reader?

Does anyone have experience with this? When I look at the numbers it doesn't make sense.

MicroSD class 10: sustained 10 MByte/sec
USB 2.0: 480 Mbit/sec. It can't sustain that, but that's a cap of 48 MByte/sec.
So wouldn't USB 3.0 be a waste?