The contact pro is a jib oriented park binding. It's not for freeriding.
The Atlas baseplate is as stiff as the Force but it has a softer highback and softer ankle straps. If you're spending more time in the park I'd recommend the Atlas, if you're spending more time riding the entire mountain then get the Force.
I'm going to disagree with the contact pro assessment.
They're carbon injected and have a responsive, but flat highback. They're on the softer side, but they are by no means only for park and Jib. They're currently Gigi Ruf's pro model and I wouldn't call him a park rat. They have more lateral flex than the Atlas/Force, but, for me, there was no drastic loss in response straight back.
As far as Unions go, Pros and the Atlas are can't go wrong purchases for all types of riding.