ARGs: stiffer, straighter, low profile rocker, fatter waist. They will be better for charging pow, spring corn spring slush and crud.
EP Pros: soft, red sidecut(w/taper), larger rocker. They will be better for jibbing around, and maby in park(although the flat spot Bents have isn't there on EPs, and they are soft throughout, so park is...different but many people do it).
If you have a park ski, I would get ARGs of these two. Personally, I will never own EPs because they are so damn soft, and now there are rockered pow skis that can't sink and still turn on a dime, also aimed at pow jibbing that are stiffer(like LL2s).