If you're wondering about steel and titanium, you should reach out to Ivan Giddings. He obviously knows a huge amount about both and would probably be happy to tell you about the differences/benefits to each material.
I got a Giddings DHWA-S mouthpiece in steel around seven years ago and immediately stopped mouthpiece searching. It just feels like the perfect mouthpiece for me in all respects.
Sean Kissane
Low Brass Specialist, Paige's Music
Principal Euphonium, Indianapolis Brass Choir
Principal Euphonium, Crossroads Brass Band