Replying to Pivot heel bindings and using them

to be honest ive been looking at a pivot heel binding for a while but wasnt really sure about it. I think that the idea is great and logical (especially after spraining my ankle last week due to early ejection.) I finally found a store where i can buy them and talked to some guys over at the shop. A few of them said that they were strictly for park and shouldnt be used for powder and other tree, cliff etc. skiing. I am wondering how legit that comment is?