For me there is not really a wrong answer here both are good for there own applications with a limited slip a Dana is hard to beat.

My new project will have a 9" because,
A) gear changes are easier
B) lower pinion location so car can sit lower with stock floor
C) gear availabilty
D)lower weight with a alum. case
and as a bonus it will pi$$ off the purists



"Just a Bracket car dressed up like a streetcar"