Interesting. It says:

What can be improved in a device that can do everything? The main RF
properties like intercept values, dynamic range and sensitivity can
hardly be improved substantially. Also the filters for the narrow band
selection can not be improved.

What is remaining? At first it is the comfortable control which can be
improved. The controls of the KWZ-30 were designbed very thrifty and
the use was therefore partly complicated. On the other side there are
now new components available which allow a different topology of the
receiver with a higher performance. The technical equipment can be
improved substantially. With this new performance level the receiver
can also be used by professional users.