I like low Bb baris because they have "fatter" tone. I simply sounds and playes better on a low Bb compared to a low A. On the other side I've never owned a better low A bari like Selmer, Yamaha, Yangisawa .... . Just low A Weltklang, Amati, Corton Deluxe (Yani stecils). There are many good bari players on low A baris. A big inspiration for me was/is Steve Berlin (Los Lobos The Blasters). He played a Conn 12 M or Buescher along with Lee Allen on The Blasters shows and some recordings. I think he is on a low A today? Dana Colley and David Woodford are still on low Bb baris. My bari is a "The Martin Baritone" but would love to own a "The Martin Magna Baritone" to low A as well. Steve Berlin on bari with "The Blasters".What do you prefer?
Never played Bb but I like the more saxophonic look