Rodenstock APO SIRONAR S 150mm F5.6

Question

HelloSorry for my poor english:-(( A buy new Rodenstock APO SIRONAR S 150mm F5.6. All peoples tell me that this lens is very sharp. But my lens is fairly soft. Seller told me that new Rodenstock lenses always softer than older one. Is it truth or not? My colleague have older APO SIRONAR N 150. It is really sharp. I shoot on 4x5 or 6x7 roll film back, Cambo SC2.-- Sigis ( - skubius laishkus papildomai persiusti shiuo adresu)