What did you have before?
There would be more pressure on the outside of the mouth with the eggbutt & d-ring. If the hole is too big on the loose ring, it can cause pinching, but its not really an issue in well-made, more expensive bits. IMO loose ring tends to encourage jaw relaxation because it is not so fixed, but it probably depends on the horse.
Eager to hear what others say!
Every great dream begins with a dreamer. Always remember, you have within you the strength, the patience, and the passion to reach for the stars to change the world. ~Harriet Tubman