I have the mason engineering bar now. It's solid. No hinges.
Most everybody says don't get a hinged one.
I've seen the BMW carbon fiber ones snap. Doesn't seem like a good design to me.
Rigidity down the axis of the bar is great in theory, but the bars have forces acting on them in all 3 axises, especially when the road gets bumpy.
I purchased the mason bar to protect the strut mounting point and increase response in turn in for autocross. Which it has.
I feel if these ECST bars were any good, they wouldn't be the cheapest one you can buy.