Mouthpiece design’s usually give a specific type of sound (either classical dark or rock bright) – on average most people pick a mouthpiece just based on how good they sound.
However, what i didn’t realise until years later, that some mouth piece designs are more flexible and make it a lot easier when it comes to playing very tricky pieces of music (ornamentals etc..)
When i got my Alto King – i found i could embouchure certain types of stuff that my other mouthpieces wouldn’t let me do in a million years.
Sound and limited capabilities – the minefield of mouthpiece types.