I have only tested that USB2, but anyway, for large files, 1 or 2GB, the flow is of ~ 7,5Mo / s, what I find low.
Certainly, it is 2X faster than USB2 "traditional", but my old transcend USB3, which already has many years of service, she turns to ~ 17MB / s, which is very different.
Reading I can only give a figure of 35MB / s, but that is definitely dù the fact that I plugged into a USB2 port.
connection to certain ports is a bit steep, but I do not think that's a bad thing. at least, when you have a key bundle hooked to this key, it is well maintained in the harbor.