I did 50+ miles in the 5 boro bike tour on Sunday with my Brooks Pro (combined total of the ride along with commuting down there and back home). I cannot recommend it enough. It does have a long break in period, but the finished result will leave your butt
very very happy. While others were complaining of their butt hurting, I didn't notice a thing with mine. In fact I often forget I have a saddle under me that how comfy it is. It truly is a very comfortable thing once it's broken in. There is no need for padded shorts either as I did the ride with my regular walking shorts and boxer briefs under them. It versatile as well because it used in an aggressive position, semi-upright, or upright position. I ride in a semi position. NOTE: this is just my personal experience with a Brooks Pro and I understand not everyone feels the same. I also have a Brooks B17, Swift, and Swallow and they are ALL very comfortable for me.
I tried an Arione just to be open minded and it was a total hassle to ride on. At first it very comfy, its when the miles go over 20miles that it was hurt my sitbone...really really bad,
even with padded cycling shorts. I did the 5 boro tour last year on it and I could not wait to get home off my bike because it was that bad. I didn't have numbness issues, it was just the saddle itself was not good for me at all on anything over 20miles. Needless to say I sold it.