I know this has been discussed plenty, but was wondering what the latest wisdom is. My 4s is still in perfect condition after almost 4 years except for erratic battery life. I 'd love another 6+ for my business line to go with my personal one, but just can't afford it right now. So, I'm going to move the 4s to the business line for a year or so, but I wish the battery life was better. I know in the past, some have said that they're not worth the effort; and of course, the Apple store would rather sell me a new phone. How are the latest replacements? Who has good ones? or are they all still not worth bothering? I can live with mine if I have to. Mostly getting at all cold wipes it right out. Would just like to improve it short of buying a new phone for now. Thoughts?