I think I'm one of the few that would say that a PEK transit isn't all that bad, but leave 2 hours min to connect... yes I've done it many times in 20 minutes but there are times when both international connection immigration and security have long lines and take a bit. I've not gotten hit with any serious delays there either surprisingly because PEK certainly has its reputation, I think 60 minutes is my max and that only happened once, otherwise it has been negligible.
Now, to your original question, if they're similarly priced definitely BR. There's nothing about the experience that is not better with BR. CA works regionally for me but long haul they'd be less appealing.