Well, my mare is trained to a level where she's doing half pass, half pirouettes, flying changes and playing with steps of piaffe and passage. I can do this in a bridle or a rope halter.
She's a nice big wamrblood and goes correctly and works well n a nice collected frame.
I have never found a way to get a lovely forwards contact In the halter like I can in a bridle...with the halter I put her in a frame and then let the reins go slack, she Carries herself but there is not the connection between my hand and her mouth, I find she's more inclined to over bend her neck in a halter to.
But it is a fun party trick to trot around in a rope halter doing dressage tricks. Actually she's a really hot mare and used to get upset about flying change until I did a couple of schooling sessions doing them in a halter,and then her changes became much more relaxed and stayed that way back in a bridle.