I like to know whether this is possible with video link....if I am watching TV on the BV 4 can someone else watch cable TV (connected to the BV4) from a link TV (DVD avant)? And would I be able to watch DVD that is in the DVD avant from the BV4? Thank you.

One of your sets has to be the master, Therefore , yes, you can watch cable on the Avant attached to the BV4 whilst the other person watches TV, but you cannot control the DVD on the Avant from the BV4 as the Avant will be in slave mode. You could watch the DVD on the BV4 if the Avant was master and the BV4 slave but remember that the quality of the link video may not be everything you want.