I agree with you, these rail seats are actually quite comfortable for a longer ride too with bare minimum padding. I have a Giant seat and a cheapo internet bike seat on a road bike and track bike respectively. I've found setting the seat in the right position makes a world of difference with both seats. To me it's more a function of seat height, seat angle and seat mount slide position front to rear and also seat alignment. Perhaps the shape of the plastic seat conforms to the cyclist ? But with some seats it's not how well padded they are and still be comfortable.