Let's get the terminology straight. We're talking about touch weight. Not soft keys. Yamaha's are known to have a light touch weight The down weight of most manufacturers grands fall within the 56-48 gram range. Verticals, by the nature of their action designs, do not have the same feel as a grand piano action. So there is little room for a large change in touch weight on a vertical, and it would be quite expensive to carry out such a change.