I bought a new saddle last week from my LBS and tried it out with a friend saturday. My friend asked me if the fitted me for the saddle, I didnt know they did that. Anyway, I went back the was fitted... it said I was 134mm, the LBS said 145mm would be great. So when I got home I checked to see what width my new saddle was. It is 187mm wide. So it it not the right "fit" for me...

my question is, does 40mm really make a difference??? I am able to return the saddle if need be.