I own both, but haven't flight tested the 4 blades.
The 3's fly great!
I like the ease of assembly on the 4 blades, and of course theextra cutting surface.

I've heard that a four blade will not penetrate quite as far as a 3 blade due to the extra drag of the 4th blade, bu tI really don't think the difference will be noticable on whitetail, especially if you stay away from the bones.