ORIGINAL: jackflap
Most (not all) of you guys are missing the intent of reducing poundage. Its not for ease of shooting or holding. For crying out loud, with 65-80% let offs, that should not be the issue.
The intent is to keep the arrow in the bird, not necessarily for more damage, but for easier recovery. You are going to have little if any blood trail, but if you have an arrow in the bird flight is limited as well as running through brush.
This is arrogant sounding, but from a guy who has shot lots of turkeys with a bow, when someone tells me they are going to use their whitetail set up on turkeys, what they are telling me is they don't know much about "shooting and recovering turkeys" with a bow.
As mentioned, even at lower poundage, you need to use an adder point or a blunt ended mechanical such as the Gobbler Getter to help slow the arrow down and hopefully keep it in the bird.
Can you successfully kill and recover a turkey with a 70# draw and a fixed broadhead? Certainly, but why not put the odds in your favor by implementing the proper set up that has proven to be most effective over many years.

Dan