Loping Hackamore comfortable for my Horse....

I bought one of these to replace the rope halter I was riding with. The halter gave me great lateral control, but didn't stay in place well on those rare occasions I needed more pressure. It was good, but not perfect. The Loping Hackamore completes the concept. It gave me everything the rope halter did, plus more. From the first ride, my finished mare worked beautifully in it.Fast forward to my other mare (a rescue) that I had struggled with for some time. There was just something wrong. She didn't rein well and didn't stop, even stopping from a walk took a lot of pressure. She would stiffen and keep right on going. I tried everything I could think of. Other than this problem, this little mare was perfect. It gave every indication of being a training issue. This was frustrating because she didn't seem to be able to learn. The other day, I put the loping hackamore on her, instead of a halter or snaffle. About 1/4 mile down the road, she let out this big sigh. She then dropped her head (which wasn't high in the first place) and her whole body relaxed. The best part, when I took the slack out of the reins and said "Whoa", she stopped. When I asked her to back up, she dropped her head, rounded her back, and said, "How far?". Evidently the snaffle caused her pain--even though she eagerly opened her mouth when being bridled and gave no sign of discomfort. The rope halter must have also hit her high enough on her face to cause the same pain whenever it would ride up from pressure. This hackamore doesn't ride up--she found it perfect.The vet has been through her mouth on several occasions and we can't find an issue. But, the horse is always right. This mare goes in the Buckaroo Loping Hackamore from now on.