BBB on O3DS is slow as hell, but that is too much perhaps.
It took around 10h for me to install 30GB of CIAs on a completely legit Samsung EVO Class 10 microSD with adapter.
This same card tops the USB2 speed on my laptop at around 30MB/s.
Anyway your card is topping the USB2 speed on your notebook too, it can't go faster because that bottleneck (and it is already going VERY fast).
I don't think your card is fake, but your O3DS is a slow PoS (like very O3DS).
Let it install and go watch some movie, party, and etc. Be used to the gatewaiting.