Well I have a 4S in the UK on O2.
As most people know you cannot turn off "3G".
I was on to AppleCare the other day and the advisor told me she can turn off her 3G on her 4S running 5.0.1 but shes on vodafone. She did tell me she knows all the other uk networks the option isn't there.
Now my question is could I download the Vodafone version of 5.0.1 so I can turn off 3G?
My wife is on Vodafone so I do have access to a voda sim if I need it!
I've never heard of that. When I was at the Apple store in Manchester (UK), I asked the 'Genius' if it were possible to switch off 3G, she said no. At the time of asking I was buying the 4s (no SIM). She didn't say 'you can on Vodafone but not on any other carrier'.
I would be very interested, like you, in finding out if it was possible and the 'Genius' was misinformed or simply didn't know.
I highly doubt this is true.. the reason I say this is apple made all iPhones 4s' the same I am assuming they did this to make one software version why would they make a separate software just for voda?