The 990's lock-on time is much, much faster. With the 950, I actually elected to not use the digital input from my cable box because my wife (who I consider an excellent test for signal acquisition time) went nuts while channel surfing. With the 990, I set it up initially with a digital input and she didn't even notice. There's still a brief delay due to the box itself acquiring new channels, but that was a problem to a similar degree with the analog audio output.