All of my dressage horses are started in Sprenger KK Ultra’s and I have always found them to be a really soft bit. But I have a 4yo by De Niro who is super fussy! I don’t know if it is a De Niro thing so would be interested to hear that as well.
He has been under saddle for around 8 months and is very trainable in his transitions, moving away from the leg, etc but he really does not like his mouth being touched. I have tried to eliminate the obvious such as mouth conformation, he has had wolf teeth removed before he was broken in, has had regular body work and has even had a two month spell.
He will only go for around 30 seconds before he chomps on the bit, has a reef or toss of the head. Any transition or change of direction he gets offended in the connection as well. He has improved as he was terrible when first broken and reefed heaps, but he clearly is still not happy. He has a very light mouth but does not suck back behind the bit. He is just very offended by his mouth being touched.
So I know there are bits that suit horses that don’t like bar pressure, and other bits for horses that don’t like tongue pressure but which are which? He is a very sensitive horse and I think he is worth getting right!