We weren't introduced to the Zero Reader until after the IRT! Once it was set up it wasn't too bad, but the roll demand was a bit lazy. I was once told that it was the same device as fitted to the Britannia...
Was that really so?
Keeping the little ZR bead centralised on the AI whilst scanning the ILS display was...interesting. Whilst remembering to tweak the elevation knob so that the bead's pitch demand was correct as you decelerated / configured.... But with practice, not too bad. I think it gave a fractionally lower ILS Decision Height - 250' rather than 270'?