The point of knowing is that if / when a website strats doing odd things, amongst the possible causes (the site itself, the browser settings etc) one may be signal strength.
All wisdom much appreciated.
Thelonious: Many thanks - the wifi world is a marvel isn't it? The main measure we can gather data for is "meaningless" as you say, while the measure that is not meaningless is too awkward to gather data for !!!!! I guess it provides scope for more R&D.
I do appreciate your reply and it makes good sense to me.