I have a B-17 on my touring bike and it's comfortable enough that I have no reason to change it. I have another saddle on my road bike that is not a Brooks and again I have no reason to change it. There are a few really good saddles available. Brooks B-17 is one of them.

As an aside. I have read about having to break in a Brooks B-17 often. My saddle was as comfortable as sitting on air from the first ride. A couple of minor adjustments to the angle was the only thing I did. I did try that same saddle on my road bike and that didn't work out at all. It was very painful. I'm thinking bike geometry has a lot to do with the comfort of any saddle.