I use a whisker biscuit so they do set in the bottom of the rest just as the aluminum do. I tested them both today, 20-30-40-50 yards and they always had a higher poi. I could shoot one aluminum then from the same stance and then carbon and it was always higher

from the farther distances you could see the aluminum with a noticable arch in the flight but not the carbon

found it quite interesting and will probably switch to all carbons......I shoot Easton Epic 400s at 19.50 inch long