I don't ever go to the tiedown unless I have to. I have, however, used it to balance up some horses on the barrel pattern and it has worked well. However, even the finished barrel horses I've had don't get the tiedown all the time. They'll get it to show in and maybe the day before a show. It's not tight either, it's just enough to give them something to reach for but not enough to constrict them.
Ruger is the one exception to my tiedown rule. I was tired of getting hit in the face. With him, it was learned habit and NOT a pain issue. A black eye, bloody nose, and a bloody lip later...I was DONE. Of course, I think once he is finished up he will be a horse to run in a tiedown anyway. He pushes out okay right now going slow, but once the speed is added I feel, from my standpoint, that he could benefit from one for the balance.
A horse that is soft in the face, well balanced, etc will never need one. One that is only running local playdays or gymkhanas loping around just for giggles will never need one. One that is only going slow will never need one. A horse who is so powerful they literally throw themselves off balance when they're trying to fire? They should have one, in neutral, to help them enhance their ability to push off.
I have never had a horse get heavy in the front end from a tiedown. A properly adjusted one should have NO effect unless the horse reaches for it. I ride the same way with a tiedown as I do without one, I expect going slow my horse to be rounded up and working from behind, soft in the face, etc. Just because there's a tiedown there, I don't stop riding and let them hit it constantly. They are only going to hit it when I go to one hand. They lose the support of my hand and get the support of the noseband instead.
Pssh.I didn't pick up the wrong lead
It's called a counter canter...
...A very advanced maneuver.