No way I'd necessarily listen to the owner. We all ride differently, we all have different hands and different training. I've found that it's a rare horse that only goes in one particular bit. It's an interaction of the rider's hands, the bit, and the horse. Multiple possibilities.
My mare's former owner, who was a good rider and a good trainer, told me that any time my mare didn't respond to the bit properly, she just put her in a Wonder bit. It was a double twisted wire! I'm not that person. I fooled around and found a nice three piece snaffle the mare loves, has a little copper quarter moon in the center. She reaches for the bit and carries it and herself beautifully. When I want more control, I put her in a Myler ported kimberwicke.