Most of the scopes from that era & generation were about the same size & weight. At the time they were state of the art, but better intensification, new technology like the MCP & so on have made the huge heavy sights obsolete for the military.
I think it's important to know that image intensifying sights aren't anywhere as illumination dependant as the older IR types.
I constantly hear reference to gaining distance with accessory lighting. It makes sense with the older IR units as they really benifit from some kind of IR floodlight. The image intensifyers nowhere near so much so. If you think it through the illuminatioin is probably about the same "out there" as it is "in here" so the intensification will be the same. Image intensifying scopes can see all the way to the horizon, but the resoultiion of the tubes becomes the limiting factoer as it prevents good target identification at longer ranges.
Allan Quartermain: “Automatic rifles. Who in God's name has automatic rifles”?
Elderly Hunter: “That's dashed unsporting. Probably Belgium.”