I got the Bari bug a few years ago. I'm mainly a tenor player - I had to have a Bari so I rented a few horns to learn about Bari saxes before buying one. (A highly recommended process because its hard to sell a Bari sax if you find out you don't like it). It usually takes me months to really know whether I like a horn or a mouthpiece.
I ended up rescuing a low Bb SML Bari from a great little companies rental stock. It had been through the war. A re-lacquer with a slightly bent main tube. Lots of professional solder repair work etc. but a sound I really liked. I could solo on this horn. It played rather well. I compared it to a couple of modern Asian horns and a Selmer Series II. Both of these I had rented for a couple of months. The rental company did not want to sell me their SML from rental stock. So I told them - go out and buy a new Asian horn - send me the bill and give me the SML. It worked.
One key aspect of the SML sound is the upper register. It does not go thin and nasal like many Bari saxes. The top end of the horn plays much more like a tenor that other Bari saxes. It suited me just fine as I am a tenor player mostly. Check out the SML Bari review on Stephen Howards web site. I agree with his assessment. My Bari is from the mid 50's, brass and I use a Morgan vintage Bari mouthpiece. The Morgan warms up the sound nicely. It's not a perfect horn but works for me.