I seem to remember being told they did away with the original off-net deal shortly after I left ntl.
I used to use Sky when I was a Headend tech to look at channels when CS would phone me up, it was usefull to see if the problem was at source.
I seem to remember being told that one Headend tech was told he had to have Sky installed for this very reason!
I don't know if there is a new deal for off-net employees, I heard they were going to re-introduce it. Although it may be like the bonus the field guys were promised last year