I do not have one, but they would be acceptable in the jumper ring. They are really for horses who do not accept traditional bridles; they are supposed to not press on certain facial nerves which can cause things like headshaking, head rubbing, etc. If your horse goes well in a normal bridle you'd probably be better off in a traditional figure 8.
I have one; I wanted to try a figure-8 but my mare is so hard to fit I gave up. She has a very short face, a tiny muzzle, and a big forehead. Now, I only do dressage, but the Micklem was a good choice for her, much better than a flash (also very hard to fit to her face.) Here she is. Note the browband is not the one that came with the bridle... It's a bit bigger.
My trainer bought one for her horse and she seemed to really like it. Her gelding now goes in that bridle primarily because he seemed to really really like being in it over other bridles. It's main goal is to be more comfortable and fit better on the horse's head.
I'm not a jumper rider, just an eventer, but my horse goes better in a Micklem, even for dressage (where it's legal and acceptable). He is difficult to fit in a flash, hates the figure 8 (even though I love it), and loves his Micklem. I've tried putting him back in a traditional bridle, and after about day 2, he stops letting me bridle him. Put the Micklem back on, and he's back to taking the bit again. He is a head rubber and will shake and toss his head in a regular bridle, even one with a comfort crown. I think they're butt-ugly, and he has such a handsome head, but I'll take comfort over style any day. Here he is in his Micklem: https://www.facebook.com/home.php#!/...type=3&theater. If you want more info regarding these bridles, try doing a search in the eventing forum - lots of folks over there use them.
"Opportunity is missed by most people because it is dressed in overalls and looks like work." - Thomas Edison
So, the Zen Buddhist says to the hotdog vendor, "Make me one with everything."
I saw this post when researching the Micklem bridle and I have to say that my horse LOVES the bridle. I actually tried the figure 8 with a terrible response from my horse. He had a big temper tantrum and usually when we would canter in it it resulted in rearing or flat out stopping.
I will say for the last 3 and a half years I have had to use a studded nose band (please don't tell me how bad of an owner I am for using one, not the purpose of this post) and a standing martingale.
Three weeks ago I found a black Micklem bridle for dirt cheap and figured it was worth a shot. I had been looking for a while a way to switch up my equipment and make my horse happier. The first time I rode in it my trainer was beside herself. I spent a week in it and even had her give me a lesson in it and still remained amazed. I have had a martingale on my horse due to the fact that he raises his head in my face when we approach fences to the point we basically pogo stick to the fence....not good. I jumped 2' without a martingale with this bridle and my horse was SOOOO relaxed.
The other day, I have since changed trainers, and my new trainer was even impressed and she had me jump a 3'3-3'6 course....NO martingale. So relaxed and responsive.
I definitely give a two thumbs up, my horse gives 4 hooves up, for the bridle! Even better it is legal for the jumper and eventing world.
I'm in the "my horse loves this bridle" camp. My youngest homebred (5 year old BWP) has always been fussy in her head. After some time off to let an injury heal, we put her in the Micklam as a "what the hell, probably can't hurt" thing. She was instantly happier and has all but done away with the fussiness. We can't attribute it all to the bridle -- some maturity and healing the previously unknown to us but nagging injury are also big factors -- but she's a happy girl now.
"I don't want to sound like a broken record here, but why is it that a woman will forgive homicidal behavior in a horse, yet be highly critical of a man for leaving the toilet seat up?" Dave Barry