I always like the idea of pivotal seats in order to save weight. But in the end the "original" MacNeil seat in combination with an average pivotal seatpost was the same weight as a light seatpost with a rail seat. So why should I give up the option of shifting the seat forward and backwards? In addition the padding, which is completely unnecessary in my opinion, is likely to get destroyed very quick when doing upside down back wheel tricks. And then so many seat came on the market which were a copy of the original MacNeil seat just with other decals because no company was big enough to spend money on a new mould to produce another seat.Years went by and now we have the Ares seat. Ugly in my opinion, but functional and from what I heard very stiff and wear-resitant. But again: The weight is not lower than a railed seat with a light seat post. So I stick to my opinion: pivotal is a good idea, but so far we do not have products on the market which really take advantage of the concept.I will keep on riding KHE Watanabe seats with reasonable alloy seat posts...