Only 40-50 MB / s and driver problems which manifests itself in data corruption ...

At first it was only twice the normal speed of USB 2 with 40-50 MB / s, not in the vicinity of 450 MB / s.
Gradually, the external hard drive was not detected until it has eventually partitioning corrupted. At the end I could only back up the data as OSX disk with read only permission (ro) ge-mounted and has to backup I got it re-partitioning. Directly on USB2 everything is OK.

I suspect there are problems with the driver, as in similar products as "Sonnet USB3.0 ExpressCard 34". The data security is at risk - it's too risky to rely on this product.