Having taken note of ardsar's probkems, I have now left my D7000 alone for a week. Still locked solid at the same speed, 71Mbps+.
I have looked at the SNR and there has been little difference in the DS SNR, between 5.9 and 6.1. The US SNR is a difference story, that I have seen vary between 7.2 and 10.6, however sync remained locked and speed did not vary.
My line is not perfect as can be seen by the fact I cannot obtain the full 80Mbos allowed, however the D7000 is faster than my OR modem and completely stable, something I could not say for either the Asus or Vigor 2860.
There is one report of it being unable to lock on a very long line, and ardsar's issues, but in general the reviews are very positive, add to that its Sky compatible too, there's not much else to say.