I'd say this is almost an impossible question to answer definitively, but I can give you my experiences.
I'd say the Cartel/Mission and the Force are very close to each other as far as what you'd expect out of them feeling wise. Stiffer and responsive straight back with not as much lateral flex.
And the Malavita and Atlas are close as far as what you'd expect feeling wise.
Both are plenty responsive straight back, but feel softer laterally.
It's weird and correct me if I'm wrong. But Union advertises the Atlas as an All Mountain binding, but I find it to be soft enough to do juuuuuust fine in the park. Whereas burton advertises the Malavita as park binding but last year's was firm enough to do juuuuuuust fine all over the mountain.
Where these comparisons start to break down is when you throw in anything using the contact/flite baseplate. This is where, I think, for non-EST bindings, Union has burton beat as far as innovation goes. Their "jib" and "entry level" offerings, to me, offer a little more variety and something quality for every rider.
Thanks man - good info. Have you ever ridden the contacts or contact pro? Are these suitable for all mountain freestyle or are they outright park?