The basic Brooks is convex, so are the basic body parts that will contact them, the result is that the contact areas upset into soft spots and the surrounding leather remains stiff and supportive.

The main cause of discomfort is not managing the upset process effectively, or riding a clapped out saddle. There may be body types that are not comfortable on a Brooks, but I don't know if that is the case or not, or just some people don't know how to ride them.

I don't personally find them super comfortable for the first half of the day, many saddles are that, the Brooks just rides better all day long, for me.