Well, I've only had largefowl but I'm fairly certain these characteristics are universal:
1. They are broody and fierce mothers.
2. The males are even-tempered and will protect their hens. Sometimes at the expense of their handlers arms, legs or small dog...
3. The eggs are large to XL and the eggs from bantams are on the larger side in eggs for bantam birds.
4. They have a beautiful green sheen that just doesn't stop.
5. They have a perfect balance between being downright gawdy and the most elegant creature you've ever seen.
6. They are very friendly and intuitive to a fault.
7. I have NEVER had a picking problem with the breed.
8. Relatively few health problems.
9. They do not have heavy foot feathering like Cochins so muddy feathers are generally not a huge issues.
10. The combs are medium in size and set close to the head. Some birds differ but hens do not have an issue with frostbite. Some males will, especially if measures are not taken to prevent drafts in -10*F temps.
11. They are highly active but do very well in captivity.
12. I have never had a Langshan even attempt to fly out of a pen.
13. They do not have large amounts of fluff so breeding/fertility does not have to be artificial in nature as they can breed successfully naturally.
I've got others!
Are you interested in eggs, chicks or adults? I'm certain I can find SOMEONE who would be more than happy to share!
ETA: See what you've gone and done Sonoran?!