I am currently running the 6.1.3 version, is it worth it up update to the operating system 7.0.4? I don't like the way it looks, and I use the phone a LOT. I use the radio, and depend on my phones battery at work. it hardly lasts the day as it is, with out me charging it on my breaks. will this new operating system slow down my phone, crash apps and overall kill my battery, like everyone says on the internet? I hear from others its worth it, but they all have the new iphone 5 or 5s or 5c. im using the oldschool 4s. any opinions?