I had exactly the problem you describe on a terry butterfly. While the transition is one good way to describe, the other is that some of those saddles are just too wide on the nose, that is why they rub. I am very happy with my Brooks Finesse now, but I did have to tweak the postion a while. For me, what was key was to level the nose, which means the rear is a bit higher than the front. But I sit very close to the edges so I wish it had a wider rear (the new b68 does). I also noticed the problem you describe when any saddle is too far forward, so you could try pushing your saddle further back on the rails and see if that helps.