Anyway, the problem with 70mm was how little was shot in 70mm. Most of the 70mm projection was 35mm blown up. It made for a dramatic picture on that wide screen, but it wasn't true 70mm resolution.
To put this in perspective, Aliens shot in Super 35 which at the time suffered from an emulsion problem leading to graininess did not look any better in 70mm.
What 70mm did provide however is a 6 track magnetic sound track versus 2 track optical.