derekl Yes, this subject has been discussed here on many, many occasions in the short time I have been reading PPRuNe. I took/take an interest in the matter as I worked in telecommunications for 27 years and started working with radio telephony in 1981.
I have read all the threads, including pilots telling us of unusual instrument responses and so forth. My own mind is still open, I have heard both sides and I believe both sides are sincere but, if a carrier has decided to ban mobile (cellular) telephones on their aircraft, then they are banned.
The same goes for hospitals where they are concerned about equipment being affected by the signal. Currently, I am regularly visiting a friend in hospital and it seems that everyone is using phones all over the place, despite instructions to the contrary.
Call me old fashioned, I do not use my phone in hospitals or aircraft, once instructed not to do so.