Same for the Beadrider - airflow keeps you cool, and dry….
I'm sure you can see that there are no simple answers. A custom seat, made by a company who lives and dies by their seat customers, is WAY better than any OEM variant. However, your riding style, weight, height, inseam, arm length, and age, all impact seating. I had Russell build a custom seat for my LT, and it required pictures of me, and my co-rider on the bike - riding and at a full stop, plus a host of measurements. 70 days later, my seat arrived, and it DID correct my major complaint on that bike, but my Corbin always felt better on the road.
The Spyder doesn't have the design issues of the LT, so road comfort was my only driving issue. I used the existing passenger backrest, and had them match the stitching. My seat is perfect - for me.