I shot quite a few animals back in the 70's where I didn't get a pass through. Since then, most have been pass through. My personal experience tells me that when the arrow stays in (assuming a decent hit), the animal goes down quicker. The passthrough definitely leaves a better bloodtrail, and it better, because most will have to be trailed a bit further. With a good hit, either is deadly. With a poor hit, I'd prefer the broadhead to stay in, but if you're lacking in tracking skills, then you probably would prefer a passthrough.