I used Sidepulls for about 20 years. I used them on everything from finished horses to breaking babies and beleive in them strongly until I had a horse run right through them and had a bad accident. Took down 3 fences and one post.
I backed away from them for 4 years but another post got me interested in giving them a try again. My young guy is about 1 1/2 years into training and is extremely light on the bit and responsive to leg and voice commands.
His problem now is I am loping alot, every chance I get and I want to steady him for the tight turns of a trail, for the washes , just about everywhere I am going but I can not pick up the reins, stready him with the reins because to just pick them up gets him backing right down.
Well I tried the side pulls 2 weeks ago and gave them a good try again. They lack the response of a bit, the weight of a rein is lost on them . His stops are just as good but they are verbal and shift of weight. Turning by neck reining is worst but the big thing for me is I can support him, stablize him in the lope, positions his head, hold him together nicely in a tight turn. I short I can pick up the reins alittle and not have him come down too far with contact.
I will continue to use the side pulls supporting the lope because now as a 5 year old he will learn to spend alot of his time at that pace.
I don't recommend the side pulls for someone without the skill the knowledge of using them. Sensitivity is lost and you could end up with a heavy headed horse.
Anyway for those that don't know what side pulls are this is my daughter on my old endurance horse. He is wearing side pulls.