I trim about 2 pounds off of a 12 to 15 pound packer. That would be 15 to 20 percent. I trim pretty thoroughly. However, I render the fat and use it for other things, so no waste here.
The reason to buy a packer is that it just plain cooks up better.
me: I don't drink anymore
Yelonutz: me either, but, then again, I don't drink any less