As I mentioned in some threads the service manager for Mazda happens to know be a close acquaintance of mine. He used to be gear head and you might have actually seen him in one of the F&F movies even! Anyways he has always given me good advice. 1 thing he mentioned is he has started to see few repairs 2014, 2015 and before of CX5 where even after brake oil flush quality of braking (in terms of mushiness - the word he used and he said softness) did not improve much. After investigation he is finding softness and swelling in the brake lines but no leaks. He was suggesting (as the manufacturer or quality has not changed between generations of CX5) to think of upgrading to better brake lines and might as well think of braided (not sure what that means). He said risk is relatively low in terms of leaks but mushiness (again the word) might increase with # of years more than other comparable cars. 1 more thing: he said BRAIDED would be LEAST favorite option as they ALWAYS cause leakage in the fittings sooner or later.