The descriptions by Prologo and Real Cyclist (and affiliated sites) are very much worth the time to wade through. In my case, my CAAD-10 came with the Prologo Kappa, a saddle that is described as semi-rounded. The saddle was fine but caused characteristic numbness that as I rode it seemed as if it would go away if the Kappa were a bit more flat so that my sit bones would take the pressure. After wading through all the manufacturers' web sited I went with the Prologo Zero PAS because A) the company (along with RC) took the time to describe to potential consumers how they expected the saddle to fit, and B) the descriptions of the Zero PAS as being a flat saddle seemed to be dead-on for what my soft tissue needed, and C) Real Cyclist's 60 day unconditional return policy gave me the peace of mind that if it didn't work I could trade it out for a different saddle. But, after 180 miles on the saddle I'm happy that I won't have to return it as it "fits" exactly as Prologo and RC describe. After decades in saddles without a cutout, this is the first saddle that I've felt comfortable enough trying a full cutout. It took me about 4 hours in the saddle to get used to the new pressure points, but am pleased that these new pressure points are actually my sit bones and not soft tissue. So, read up and study the Prologo and RC web site descriptions, assess those against what yo unlike/dislike about your current saddle, and give this a try if it seems right. Saddles are definitely and "experience good" so RC's unconditional guarantee takes the risk of a new saddle out of transaction. I just wish the carbon rail version would have been available to drop a few grams, though this Zero is certainly a reasonable weight given the price.