They were impressive, if somehow bland at the same time
I saw the WTC towers from a ferry during a trip in 1977. They were
gleaming and impressive - they certainly stood out from the rest of
the building around them, though of course the Empire State Building
and the Chrysler Building also stand out and have more "character"
to them.
It was almost like someone took two buildings from the future and
planted them right in the middle of a village made of concrete and
brick. Back then architects envisioned their style being the future
of what all skyscrapers would look like in NYC some day.