A traditional saddle has rails that locate into the clamp atop the seat post; it’s a simple design that works well and saddles have been honed to perfection over decades.
Changing that to an I shaped beam that locates between clamps atop the seatpost is hardly revolutionary – it’s just another way of accomplishing the same task. The problem is that an I shaped beam is not going to be as forgiving as two small diameter rails (that can be tubular).
The saddle hull itself will have to be designed to flex a lot more in order to get the same deflection characteristics as a standard saddle setup and the same level of comfort. But we didn’t find this to be the case, feeling the Kore I-Beam saddle to be harsh and uncomfortable. The 2014 aluminium alloy post is very well made, and fitting is simple with a huge amount of fore and aft adjustment available, but it’s all at the expense of a dramatic loss of comfort. Also, it’s no lighter than a standard rail setup of equivalent price.