Bobbie, as I said... the "original" Mikmar bits basically are a combination between a gag, curb, and port bit. Some horses will feel very constrained with that type of bit.
We carry them at my store, and the mouthpiece is VERY very thick. Again, a benefit for some horses, and a deterrent for others.
I would HATE to see these bits in the hands of a green beginner (I am not saying anything about anyone here, but rather for anyone who reads this) as I do think it's a more severe bit than others. Having said that, I would like to try it myself just to get a real sense of it.