Gryphon Rider too weak/costly?

[Vynd]

I think the Gryphon Riders are fine. Sure, maybe they're not as good as the very best knights and knight equivalents in the game in terms of pure toughness and power, but they make up for that with their flight. Are there any recruitable flying units out there that are better, 1 for 1?

What's so awesome about the other Amazonian sacred troops, anyway? I got my first look at some Onyx Amazons the other day, and I was not all that impressed by their sacred unit. The Jade Amazon cavalry is nice, but didn't seem truly remarkable to me. I've never checked out the Diamond Amazons, I gather they're the coolest?