The B&T joint is CV joint, the typical u joint is not a CV joint. I suspect Mopar phased B&T out for cost and maintenance reasons, as they are a better design in reality. I can't comment on their ultimate power ratings, other then anything mechanical has a design limit. Mopar using a CV with a typical u joint has more potential vibration design issues then two properly phased u joints, and I don't know exactly why Mopar went with a mixed joint solution back in the day. I would think with only a single u joint, the less angle the better.