I didn't have as good of luck with them. In .177 where the JSB's fit snugly into the chamber the AA's were loose and my Hunter Elite didn't like them at all. The CFX seems to like them though. It's all or nothing on the AA pellets. I too posed the same question as yourself and had a few people chime in who said that the skirts were different. Or that the undersides were different or something. They're cheaper than the JSB's, that's for sure.
I dunno, I've heard and read different reviews on them. I prefer the JSB's if I'm not shooting FTS which I mostly use. Get a tin or a used tin and see if the gun in question likes or dislikes them.