I've used it for the past 6 years on mine and think it's great. Never had any problems with them heating up on it (and they were both the types who didn't need feeding as an excuse!). also used it for my veteran as she wouldn't eat 16+
I've used their Build Up cubes and found it very effective for putting on weight, but did work out rather expensive, so have switched to straights instead. I wouldn't feed it to anything at risk from laminitis or sensitive to cereals though!
Had my mare on it the first winter I had her and although it kept her weight nicely she was a bit nutty. Swapped to Spillers Showing and Conditioning Mix and she was much calmer but still in great condition.
Tried it years ago on both my sisters TB gelding and my ISH mare and both came down with laminitis. Dont know for definite it was the build up that caused it but seems too much of a coinsidence
yup when i first bought mickey he was very very lean and i fed it to him and it was fantastic we tried quite alot of feed before to try and put some weight on him and that was the only thing that worked really well but it did make him buzzy1 my gran feeds it to all of her youngsters and there in exellent condition but it sends alot of them loopy!