Impressive for its time, 1959. But it does not hold a candle to an M1A2 Abrams, or some other current modern MBT. For example, it weighs only 60 tons vs more than 70 tons for the Abrams. Its engine had 1000 hp, while the Abrams has 1500. The armor was up to 319 mm. The armor thickness on the Abrams is classified, but it's composite armor, and I've seen estimates that it is equivalent to at least one meter of steel at its thickest. The operational range of Object 279 was 300 km, while the Abrams (considered very thirsty by modern standards) has an operational range of 426 km. The only thing bigger was the gun, with a caliber of 130 mm, vs 120 mm for Abrams. But the muzzle velocity was only 1000 m/s vs more than 1500 m/s for the Abrams.