USB 3.0 will offer over 10 times the transfer speed of USB 2.0 for a top speed of 5.0 Gbits/s. USB 3.0 is backwards compatible with previous versions of USB (2.0/1.0). It is important to note that in order to be able to fully utilize USB 3.0 speeds you need to have a device that supports USB 3.0, an USB 3.0 cable, and an USB 3.0 port. Not having the following means that you will only be able to use USB 2.0 speeds.
In some cases overscan or underscan can be the issue with displaying your Mac's display properly. You can deselect the overscan option by going to Display Preferences > Options. If this does not resolve the issue, adjust the aspect ratio on the display (check the manual of the display for specifics on how to change it.)
Using "Sound" Settings under System Preferences, or using "Audio MIDI Setup", select the "HDMI® Audio Device" as the audio output. This will switch the audio out from the built-in speakers to the adapter.
Product number 6630 has software that is not compatible with windows 8.1. Installing the program in Compatibility Mode for Windows 7 will work.
Product numbers 5969 and 6331 are both powered using the USB connector on the device.