What does that affect exactly? I only noticed the calibration being out of whack on vocals and only when I used it at my cousins with her TV. That was also on the ps3 so I'm not sure the differences there, as well it was rb1. But, would if affect the guitar and the drums as well?? The vocals seem fine on my system, there's no delay which was what I experienced at her place.
Let's say you have a note. We'll represent that note with a big O.
Now, we'll have the virtual "timing window" you have to hit the note. That "timing window" will be represented by vertical bars ||.
The note, O, should represent the exact center point of the timing window, ||. Thus,
|__O__|
If your calibration is off, you'll get something like
|____O|
Where it feels like you can hit the note way early but have no window at all behind the note, or conversely
|O____|
which is the opposite, early won't work, have to be late.
This also applies to sound. The sound the note, O, should be associated with should also match up with the exact moment (or extremely close to) the note crossing the hit bar at the bottom of the note highway.
Lag can even get worse, to where the hit window is perfectly centered visually but the sound doesn't come until later. etc.