Shape-up - anyone used it?

[katie_and_toto]

My pony is a very good doer in the summer, as soon as the weather warms up he balloons! Normally we give him soaked hay and more exercise to help keep his weight down, but have heard of Saracens new feed Shape-Up. In the summer Toto just has a handful of Hi-Fi Lite so he can have his Brewers Yeast everyday, but would it be worth getting some Shape-Up? Am a bit sceptical of feeding a mix to a good-doer but obviously Saracen have spent years developing it. So has anyone tried it or heard anything about it?

Thanks