When do you sit on your seat. Almost never. So you don't need padding. OK agreed.
Everyone runs their seat at the same angle and the same height. Yes? Yes.
So a seat and post in one, what's the problem? They were around in the old days and now they're back and smelling suspiciously of trendiness.
Fly have been working on theirs for at least a couple of years, but still isn't available. Nothing wrong with that, you'd hope that they'd be testing it, redesigning and testing again. That's pretty much how Fly, IMHO, have so many good and innovative bits.
They say they've been testing polymers for the seat, getting the mix right so it's rigid without being brittle. They also added the aluminium sleeve to the inside of the post to stop the post crushing when you tighten the clamp. I don't have a weight for the seat, but I guess it's light, cause otherwise you'd just have an aluminium post wouldn't you?
KHE banged this one out a year or so ago - plastic seat on a ali post. The whole baseball thing? I don't know. Just... why? And I've had a couple of bad experiences with KHE parts that just seemed like they weren't thought through 100%. But I'm sure this seat is perfect - go on buy it.
When eclat came along with their hundred or so products all at once last year, one of them was their "complex" seat/post combo. Looks ALOT like the KHE seat, especially the underside, and it's also plastic with an aluminium post. Taiwan is a small island you know. Which came first? Who cares.
KHE Loyal Seat / Post Combo: Weight 190g / 6.7oz
Eclat Complex Seat / Post Combo: Weight: 179g / 6.3oz
Or you could just go one of these. Beautiful isn't it? There's even some a fake carbon fibre stickers for that extra bit of race cred. Fuck these things are fast.
Uni Race Seat / Post Combo: 147g / 5.2 oz