The Sony FE 70-200mm f/2.8 GM II is an all-new design with an impressive reduction in the element count (now 17, down from 23), which results in a 29% reduction in weight from 1480g ==> 1045g! That’s a difference which is easily felt, and it makes the new design much more portable and practical as an all-around shooter.
Whether it raises the performance game to state of the art is unclear. While the element count is way down from 23 to 17, the same number of XA and aspherical and special-glass elements remains the same. But clearly something has changed in a major way that allows 5 lens elements to be eliminated.
As a practical matter and especially with ultra-high speed cameras like the Sony A1, focusing speed and accuracy are critical for a lens of this type, and for that Sony has included 4 high-performance XD linear AF motors. This should leave the old design feeling super clunky by comparison and deliver state of the art performance as good or better than anything else on the market.
Four high-thrust XD Linear Motors and advanced control technology deliver up to 4x faster AF than the SEL70200GM. Focus tracking capability while zooming is improved by approximately 30% compared to the SEL70200GM.
Also of practical note for video usage that is also excellent for stills, “the latest lens design technology reduces focus breathing, focus shift when zooming, and axis shift when zooming”