I have a myler bit for my mare.
I'm sure I could have gone with a double jointed bit, but I did research and liked what they had to offer and I liked how the bit was made/shaped.
Every horse I've ridden in that bit has gone wonderfully and I've never had a problem. I could have just been coincidence, but I like to think differently.
The current bit I have now is a Korsteel (sorry if I spelled that wrong). I have a myler bit in my tack box but it was just a "get me through until I get this bit". I am planning on buying another myler bit within the next year...or maybe my fiance will get it for me for christmas (*hint*...maybe I"ll be lucky and he'll read this haha).
Personally I've had alot of good experiences with myler bits...but yes some look scary
I just bought a myler bit about a week ago and love it. My mare is very responsive to it. Its nothing real severe. It has a low port on it and she loves it to. I noticed when I changed bits she doesnt play with this bit. She is very rounded when I use it and I have to do less to correct her. Granit if you have heavy or harsh hands any bit can be bad. I tend to be very light on her mouth to begin with so this bit works really well. I would think if you had heavy hands you wouldnt want to get one of these. Just my own opinion but I really like it. Glad I paid the price for it, was a good investment. They also say you shouldnt ride in the same bit for more than 3 days. Its good to rotate bits. Keeps horses fresh. Just my thoughts!