Do these compressors operate more efficiently at high pressure ratios? I find little concern for the weight savings considering the turbine and shaft are much heavier. Also the said savings are near the center, reducing moment of inertia little.
They are lighter, but yes the majortiy of the mass is on the shaft itself and turbine wheel head.
We shipped out 10 of the ETR 76's and 80 combos for several customers on here, see some results posted soon enough.