for me, the xl is just too heavy cause i move my eggs around so much. the reason i got the medium as my first egg was so i could pick it up and carry it into the rv for the nascar races. i strap it down between the twin beds in the back.
i'd say get the large and if that ain't enuf for ya, get another large.
with that said, i've never cooked on an xl, but i've seen one in action before.