It is my opinion that any of the above methods can be useful. My reservations are usually more related to the expertise, judgement and/or skill of the operator than to the medium being used.
We use the Syncrometer to evaluate the pads, but will only rely on CTS Originals due to the confidence I have on the operator and the consistency of the results.
I know you have great expertise in the area, Lapis. Would you like to share some of your thoughts with us?