I've played the JJA75 exclusively for the past 12 years and love it.. You will find it has a large tip opening (like .102 or thereabouts) which might mean you have to use soft reads in order to play it, or maybe downsize the mouthpiece to a JJA55 or something.
To play soft and mellow takes some physical effort but is possible. But what this mouthpiece really excels at is playing loud and bright. You can really fill up a room with one of these. If you wanted a more balanced approach to your sound, try a regular Java A75 - which in the whole scheme of things is still a bright mouthpiece.