To offer a counter side, I shoot light weights due to rotator cuff problems and surgery.
While I advocate lower weights for deer, I haven't been impressed with 3 blades in the lower weights. Granted, I've killed the deer I hit with lower weights and 3 blades, but none of the hits passed thru.
Compare that with 2 blades or 4 blades/with bleeder like a Magnus Stinger or Steelforce Phathead and at least in my personal experience, there's no comparison. But that's just my personal experience, I'm not saying anything about the experience of others.
I've had better penetration with Stingers out of a 30lb bow than with Razorcaps out of a 42lb bow.
That's just me and I don't doubt the success of others. But as long as I'm resigned to low weights due to shoulder problems, I'll personally never shoot a 3 blade again.