I've got a stock D4 and just received the update yesterday. 4G connection where I live was semi-reliable but the phone would seamlessly switch between 3G & 4G. Now since the update it does not seem to do so and stays on 4G and frequently gives me "no data connection" messages.
I do have an app that lets me switch between 3 & 4G but it was nice not to have to fool with it and have the phone utilize the 4G connection when it could.
Is there a way to revert back to the previous software without rooting? The internet browsing worked much better before the update.