In the very early days my friend Jürgfen Suttner restored two of my Jeffries and my Linota and took measurements of the instruments. As a good German engineer ( his father had an engineering company ) he further developed the principles while sticking to the traditional ways. I had both my 38 key Jeffries and a metal ended A4 on a skale. If I remember rightly, the Suttner was 400g lighter. Sound and action are quite different, but it is realy hard to decide which one is "better"... Try to play as many as possible different instruments before you spend so much money! If you can make it, go to Chris Algar's place and spend an afternoon testing. I picked my ES ME TT out of a dozen similar boxes.