Realistically none. Technically a blade with a larger cutting diameter or more blades may cause more tissue damage, but the question would be is it enough to make a difference. I have never shot a 4 blade head, but I have shot two blades and three blades in both fixed and mechanical in various cutting diameters. To be honest I have never seen a real difference in recovery times, or the time it takes for the deer to die. I have also talked to a lot of people and have never seen a distinct advantage of one over the other. Recovery distances and times are all over the place with no definitive edge towards the larger head or the head with more blades.

My quickest kill was actually with a small 7/8 inch three blade head.

The larger cutting diameter or a 4 blade head can reduce penetration though if you shoot a light set up.

Paul