Actually, an Autarch with Wings can really buff out a Swooping Hawk squad.
Give him a mandiblaster and a power weapon, and now he and the Exarch make up an honest-to-god jump assault squad. Very nice for eating up shooty units hanging out in the back field.
Or give him a Fusion gun and you have one of the best tank-hunting squad out there. Shoot 'em in the back for 8+2d6; if there's anything left, assault with Haywire Grenades.
I've not tried either of these out yet, but I'll be damned if they don't look sweet
PS - You can probably do the same with Warp Spiders, but I think it's cheaper and more efficient to use Hawks.