I have been a professional musician for many years performing in a variety of different settings - function band, solo, recording and hotel work.
I previously played the Bari 66 soprano mouthpiece, which I believe Branford Marsalis plays or has played. To be sure, the Bari 66 is an excellent mouthpiece. However, I decided to buy this mouthpiece 'blind' purely because I love the Gottsu Alto Sepia Tone 7 so much, and it hasn't disappointed.
I find it to be a sweeter more mellow sounding mouthpiece than the Bari 66. The control, focus and intonation are flawless even at the extremes of the instrument. As it is shorter than a standard mouthpiece you will have to push it further on to the sax for it to be in tune. I use a Rico 'Harrison' ligature with it, which works well.
Whilst the Gottsu Soprano Sepia Tone 6 is more expensive than a quality stock mouthpiece such as the Bari 66, to me it is worth the investment. I can understand people being reluctant to buy an 'unknown' mouthpiece but all I can say is it's excellent and you won't be disappointed. Highly recommended!