I don't believe in the Specialized sit bone measurement device, at least at the one at the LBS I went to. They just asked me to sit on a piece of memory foam and looked for the distance between some vague sit bone indentations. The size they recommended was too wide. Maybe the person who did the measurement did not know what they were doing.
I got the Specialized measurement and was recommended a 155 mm. The saddle that ultimately has been the most comfortable is a Cobb Cycling, which is 130 mm. I'm still not 100% satisfied, and don't know if I ever will be. I have been looking in at SMP Selle Avant also. Expecting to take a test drive in a few weeks. The good thing is that I can live with the Cobb if the Selle isn't a major improvement.
I'm afraid that I've become obsessed with finding the "perfect" saddle. Does it really exist?