I agree with the previous posts regarding their disposition. There are a few nutty cattle in every breed, but Chi influenced cattle seem to have a higher percentage than most.
From a commercial stand point, assuming you find some good disposition Chi cattle, they are probably best when crossed with cattle with too much fat. However, in my personal opinion, if I was trying to add leaness to my calf crop I would likely use a Limousin or Charolais bull. I may even try a Romagnolia.
A couple years ago I saw the Chi association's breakdown of "Active Members by State." Indiana and Ohio were the two top states with active members, and neither of these states is very big in overall beef production. However, the club calf business is huge in these two states which I think indicates where this breed is mostly used; to produce show cattle.
There are dozens of breeds of beef cattle and everyone of them offers something unique. However, if you're interested in producing breeding stock to sell to commercial producers I think there are several breeds that are a better choice than Chi's or Chi-Angus.