I agree that it takes 100 miles to really tell if a saddle is acceptable. Although I dumped the Arione for unspecified discomfort after having ridden up to 250 miles on one.
I think it takes about 50 miles in one go to decide if a saddle is worth riding further. I always said that any saddle is acceptable up to 25 miles, but then I bought my fatbike. That thing felt like it was splitting me in half right away.