Most musicians adapt to their instruments. They learn to cope with an instrument that is just a little bit annoying. Small inconveniences that usually can be amended with little effort.
It is strange that alterations to instruments are as rare as they are logical. Alterations make a good instrument into your own instrument. A saxophone is an industrial product that meets an average standard. My approach has always been the other way around: to adapt the instrument to individual requirements. Doing so, it gains in value as a more playable and even as a unique specimen. This chapter is about such alterations, all of which were carried out on actual instruments. Under «SOME EXAMPLES» you'll find slide shows which provide the necessary pictures.
Improvements in the way in which an instrument feels largely determines how happy you will eventually be. Some examples: thumb positions, the form of both thumb rests, the exact placement of the sling ring, that kind of thing. As far as mechanisms are concerned, C#\G# linkages, for instance, are an interesting addition to older instruments.
This is just about intonation. Saxophones tend be out of tune, mostly on the sharp side in the upper end of their range. Sometimes that can be amended, sometimes not.