AFAIK, method claim is weak against manufacturer because only end user may use it.
OTOH, invention using all old hardware but only new way to use it, e.g merging different inputs from different sources and then using boolean logic on the inputs. What is the best way to protect against manufacturer?
Also I must consider the fact that unauthorized software could have the same function for free but can not go after them (very hard to catch them, user can download it from anywhere..)
Example, smartphone with dedicated face recognition, can't claim smartphone with camera (already exist), a method claim could be done but very weak in practice.