No first hand knowledge of the rabbit product here...
Though the concept has been around for some time:
http://www.hauppauge.com/site/produc...a_hvr950q.html
and one of several variations on the idea:
http://www.silicondust.com/products/hdhomerun/atsc/
I own and operate several HDHR units... Quite happy with them,
http://forum.tvfool.com/showthread.php?t=820