I'm not sure it can become more comfortable. The traditional leather Brooks saddle become more and more comfortable with time because it takes the shape of your bottom.
That could be a good idea to reduce the length of the seat tube, as I said the Suntour does the job really well. Now I can forget the old cobblestones of Paris. I think the Suntour NCX and the springs of the B67 Brooks saddle are a perfect combination. Brooks saddle are not soft saddle. You have...
I 'd say that it goes 3 ½".
I like my Brooks saddle if it's what you asked. It's not a soft seat and it has to be made by riding and riding again. But once it's done it's a pleasure.
I put a Suntour NCX on my Electra, six months ago. That's really efficient, it gives you the confort you don't have with a hardtail bike. My old bike says thanks.
The best purchase I've ever made for my bike and for my back. Many streets in Paris are made of old cobblestones, my bike is a hardtail so you can imagine.