the red eye is usually late taking off, but they build so much extra time into it that they say it arrives on time, even though arrival can vary by 40 minutes and still be on time. That's usually due to Heathrow though.
I know they use the same planes on the route all the time, because you get to recognise the odd paint flecks round the door, and nicks in the seats, tables etc.
Once I flew up on the red eye, and back on the 14.15, which of course was late. It wasn't so much it being late that annoyed me, but the fact that they said that it had had delays coming in from Europe as the reason, when I was in the exact same seat and knew it had only had time to get from ABZ back to LHR and back up again since the morning (with the BA hour + turn arounds). As the red eye had been late, it was just the knock on effect, but the invented excuse was just not necessary (unless they rellay think of Scotland as being Europe?)