The group always had a Pop sensibility, communicating its ideas via an eponymous occasional magazine (meaning architecture plus telegram) that drew heavily on comic-book graphics and the collage techniques of artists such as Richard Hamilton. You just know that they grew up wryly enjoying the adventures of Dan Dare while they did interesting things with the girders, wheels and brass cogs of their Meccano sets. But so did other architects who later evolved into famous purveyors of the style known as high-tech. Archigram was different. In sci-fi terms, they leaned more towards the transformative optimism of early J.G. Ballard ("The Unlimited Dream Company", say) than the darker vision of Philip K. Dick ("Blade Runner"). They were always socially as much as technologically engaged. 
The whole point was the dreaming, not the building. In fact, Archigram was not very interested in buildings, or static objects of any kind. They hated well-mannered, gutless modern architecture. Given that several of them were making a living at the time designing the new Euston Station, they were reacting against something that they paradoxically embraced. Archigram's manifesto position was change and movement and flexibility. It saw the future as nomadic, a future that conventional buildings could never contain.
