I've been holding off upgrading from my 4 because I live in an area with no 3G signal at all and if I forget to toggle 3G off (in Settings/ General/ Network) when I come home, I often lose the signal completely. I only get a usable phone signal back when I toggle 3G off. I'm in the UK on O2 BTW. There are lots of threads about this issue but I haven't seen one which simply asks for the info (as opposed to endless & pointless debate about "why would you want to do that?"/ "I can do it on my 4" etc ) So, just for clarity, if you have a 4S and you've now updated to 5.1, please could you post a very quick reply with your country, your network and Yes or No to the question, "can you toggle 3G on/off in Settings/ General/ Network?" Cheers!