In 1964 I was an F/O on the V720 & V832 models and hated every minute of it.
Whilst it was way ahead of it's time it did not have a very good safety record at all and being a single spar did not help the feeling of dread when flying it.
It was not all all comforting nor nice to fly in it , was always apprehensive.
The happiest day of my aviation career was leaving the Viscount to fly the B727.