It works as described for USB 2.0 with a TF101. I don't have a system with a 3.0 port to test so that is an unknown.
If you are buying this to charge your Transformer there are a couple of thing I learned the hard way. While it will charge the tablet when connected to a regular 5v usb port or charger it is VERY slow; on the order of days! and it would not charge the dock (keyboard) The original charger will connect to anything plugged in supplying 5v and if it gets the right signals on the data lines telling it the device is a Transformer the voltage is bumped up to 15v. My original charger was toast so I cut off the usb end and wired the cable to a 12vdc 5A adapter. Now it charges in about 45 minutes charging the dock too.