I haven't been to Premium in a while (see my post at the top of the page), but last time I went they had a ton of MSF's and pigments. Also, you are more likely to find newer collections at Premium (ie: Style Black, and I think I've seen things from So This Season or whatever that collection was in the fall). I was in Prime yesterday and they mostly have pigments and nothing too spectacular (sorry Crystal, lol). When I go there, I usually shop from the singles container which is by the cash register, but I cleaned that out yesterday...to me that's where all the good stuff usually is. I think they both tend to have the same eyeshadows, Premium just has more (it also has more lipsticks and lipglosses). Both of them have holiday 2009 sets, but Premium also had the mineralize duo eyeshadows from the holiday collection. I don't remember specific names of things I saw in Prime because I went in there for a couple of things (Light Over Dark Mineralize Blush and the Lustre Drops from Style Warrors). Hope this helps a little.