After trying my youngster in a variety of bits, he has chosen a Myler level 1 comfort snaffle wide barrel with eggbutt cheekpieces as his favorite. He will still play with it if standing around, but is quiet in his mouth when working. I wasn't very familiar with the Myler levels so I went looking for information. Level 1 is advertised as being appropriate for young horses (check) with challenging dispositions (at times!). It is also dressage legal, which is good as we are planning a dressage career. So I went out and bought one, since the loaner from my trainer was a tad big.
I continued to do some more research on the Myler levels, and my initial assumption that the level 1 was mild, seems to be wrong. A few places recommend moving "up" from level 1 as soon as the horse is more accepting of the bit. And one site went so far as to say, while it is dressage legal, it is probably not the best thing for your horse!
Then there was this bit, marketed as a level 1 comfort snaffle, but with a gag action and a twisted mouthpiece.
Can someone explain the Myler bits to me and how two VERY different bits (in my uneducated opinion) are classed in the same level?
Also, why none of the higher level Myler bits, which are marketed for horses of more advanced training are not approved for dressage use (maybe I'll post this specific question on the Dressage board)
I'm not usually one to buy into marketing hype, but my horse really does go better now in this bit.
In my experience, the Myler levels seem to refer more to the shape of the mouthpiece versus the severity. A Level 1 bit has a simpler shape, really just following the contour of the mouth. So something with a smooth mouthpiece and another with a twisted are both Level 1 because the actual shape of the mouthpiece is the same.
Higher level bits have more of a port and tongue relief. If your horse is happy going in a Level 1 snaffle, I see no rational reason to change the bit because of the Myler company's marketing.
Leap, and the net will appear - A Salty Piece of Land, Jimmy Buffett
The Myler level one comfort snaffle is basically a Mullen mouth with a curve that fits the shape of many horse's jaws better than a plain mullen. The Myler snaffles with ports are intended to provide space for horses' who don't like a lot of tongue pressure.
I had a Myler ported barrel mouth with plain D cheeks for one horse. For the first six months I swapped back and forth between the Myler (jumping) and his loose ring French link (dressage). Then I decided I wanted the same responsiveness in the Myler that I had in the French link and rode exclusively in the Myler for the next six months, really working on our dressage. He was much more comfortable in the Myler and disliked the French link after that. He had always preferred smaller diameter bits, and the tongue relief must have been the clincher for him. We did have to show in the French link, but he was aimiable enough to accept it despite his preference for the Myler.
Some horses prefer a more stable mouthpiece like a Mullen, and if the Myler comfort snaffle shape fits their mouth shape they will be very happy with it.
1, 2, and 3 simply refer to the degree of the port.
It has nothing to do with where the horse is at for it's training. Only 1 is allowed in dressage because ports are not allowed, unless on a pelham with a double bridle.
Myler actually does advertise the levels of bit for specific points of the horse's training progress. I've seen an official Myler bit display and on the side it describes what the OP is saying - ie. level 1 for young/green horses with challenging disposition, level 2 offers a bit more tongue relief for when the horse is further along in its training, etc. Level 3 is for the highest-trained horses as it offers the most tongue relief. I do think this might be more geared towards the Western world in terminology but they are using it as a guideline for what level to select.
OP - I think if your horse likes the bit you've got and it's legal for your discipline, then don't worry about it!
I've spent most of my life riding horses. The rest I've just wasted.