Standby Time Usage Time Restoring as new didn't help. iPhone 4S

Sorry for bringing up this problem again, but there seems to be no official "cure" for this kind of notorious issue. As for me, I started to experience this since the introduction of iOS 5.1, which means my 4S was at 5.0.1 at the time. I've been surfing all over the Internet for an absolute answer but still no luck. Here's the list of all the things that I've found and tried but didn't work:

Turn off ALL unnecessary things that are most likely to drain battery, including 3G, Wi-Fi, Mobile Data, some push notifications, location services, automatically set date & time, etc., which there was nothing wrong with prior to the upgrade notification. (And personally, I don't see any point of having to turn off most of these wonderful features all the time)Remove my e-mail accounts, reset all settings, hard reset, then re-add the accounts.Turn off Wi-Fi, turn on 3G + Data, wait for a while, turn off 3G + Data, turn on Wi-FiReset all settingsRestore as a new phone

Pretty sure that these are all the solutions available and none worked out for me. Please help.