I would say quarting away every time. From my experience it is a higher percentage shot than broad side.
Reason: For a quick kill with lots of blood (except spine)you need to hit: spine, major artery(along back bone into back legs), liver, or heart/LOWER FRONT long. And as you know all these targets are small except heart/LOWER FRONT long area. This area is most open on a quarting away shot. On a broad side shot half of this area is covered up by the front sholder. To many times on a broad side shot you tend to hit back on the lungs and/or get one lung (from a treestand). Also on a "broadside" shot they sometimes tend to be slightly quarting tword and you get back even further on exit. Yes, it is true that if you hit the far side leg on a quarting away shot that most likely you will not get a passthrough. However, you will not need a passthrough because the deer will be laying in sight of where you shot it.