There is a downside to the bag method although I've used it before too. Because the turkey is in a bag you don't get concentrated liquid and browned bits on the bottom of the pan for gravy. the liquid that accumulates in the bag is not very good. Other than that, the turkey itself cooks fine.
I've done the martha stewart cheesecloth method the last few years, and like it better. I'm not a gravy fan but our guests are so this works better for us. Just a thought.
"If the world were a logical place, men would ride side saddle." Rita Mae Brown