I used a Callet Jazz with a Callet 10S(28 throat and 4 backbore). This was a free blowing combination.
I tried a Conn V1 with the same mp and the horn was 'stuffy'. I used the same mp on a Lawler 26b and the horn was tight, but not stuffy. On my new Committee I use a Callet 10c with a more open backbore and guess what..FREE BLOWING!! 8)
I think there is a difference between 'tight' and a 'stuffy' feeling tho.
Alan