Jebus, Daye, sorry for the run-around by the noobs, but like Mactronix said it's respectable.
In relation to you post in the soundcard forum (which got a similarly warm reception), the XFi has more options for both processing and outputing the sound including analogue out. The audio part of an HD4K is strictly for sending a digital signal along the HDMI path for an external decoder to handle. It (the HD4K) will also allow you to send 7.1 DTS-HD Master and Dolby TruHD to an external decode/AV system whereas the XFi is limited to compressed formats.