I have a TWH and I have to do the double back thing a lot when I am riding with other people. Usually one or two of them are QHs, too. We always whiz by! I am working on having her slow it down when I say so and it is improving, but she has a great big overstride so she will always naturally be faster. I mean, that's what they were bred for, right? To zip comfortably across huge plantations?
Now I've figured out that she will usually slow down if she is in the lead. It's like we are in a walking race until then though!
**I must not forget to thank the difficult horses, who made my life miserable, but who were better teachers than the well-behaved school horses who raised no problems.**