Mine came in today and I tried it out with both of my geldings.
My 17 year old ottb, in 5-6 days of moderate work, jumping once or twice a week over small fences with decent flatwork (neck and hock arthritis, so just training level dressage, nothing crazy) did about 8-9 mins of walking and then a circle at trot each direction. Felt great trotting under saddle lightly without it afterwards!
My 11 year old is the one who is really struggling. He had some time off a few months ago, and now we are back under saddle and back to really struggling with his canter transitions (picking up the left lead in general, and lots of head tossing, bracing, popping up and leaping with both leads). His hind end is pretty underdeveloped-standing behind him he’s a bit pointy still. He did maybe 6 mins of walk on the lunge with it on before I took it off and rode him. I was surprised how he felt after that short amount of time with it on. He just felt bigger-tracking up better, lifting his back better, he felt like he filled up my leg better than he typically does if that makes sense? It was almost like he just remembered that he has a butt and can use it…and while the canter transition wasn’t perfect, he didn’t flip out nearly as much. Perhaps this is a more helpful tool than I realized even when used very sparingly?!