Now major piano action improvement with use of software measurements!!
Most pianos produced since 1980 and sold in USA. Most mass manufactures could not afford the quality piano action components with well made parts because of cost. Now we have a tool and knowledge to correct these pianos that have poor control, uneven touch, to light or to heavy, and usually both. We find gram differences on each piano of 20 grams variation thru out the 88 keys. Note most average pianos now in 2021 have an industry average of about 53-55 grams down weight. After our weight balancing there is only 2 grams variance thru all keys.
What I have observed is the pianist now can play with expression and dynamics because they are not fighting the mechanical imperfections inherent within each individual instrument!