I have fed it and love it. Even my very easy keeper has lost weight on it and I mean he can really get fat on air. As far as feeding him the recommended amount he is only getting the maintence level and he does get worked with alot. So you can only determine how much to give. He is looking great tho and feels good.
My other one that I am feeding it to he isn't a hard keeper at all, getting worked just as much as the other guy, and he is even smaller being 31" but he gets fed a lot more. Currently getting 1.3 pounds of grain a day and 2.5 pounds of hay a day. While my other one is getting fed .9 of a pound of grain a day and a pound of hay and he's near 33".
They are all different. Some will do better then others on this grain. I still question how the younger ones do on this grain but some have had great success with it and I'm so far very happy with it.