I put my new B17 on my Trek 7000 last night. Right now I have it set up so I'm sitting pretty straight up, but it has an adjustable handlebar stem, so I can lean it forward and lean forward more.

I notice if I'm leaning forward versus sitting up straighter, the saddle feels quite a bit different. The shift in how I'm sitting changes what part of my body is on the saddle. How do you know you're sitting on the saddle the "right" way?

My commute is only 2 miles, so I could ride on a piece of cardboard and not really care. I need to wait until I'm feeling better to go on my longer morning ride, and that should answer the question about whether sitting up straighter is going to be comfortable or if I should got back to leaning forward more.