okay, I have an eight GB four S. It is running the latest IOS seven. My question is should I update it to 8.1? yes, I know it will slow the phone down, but my question is, how much? is it going to be so slow that it will make me want to toss it at a wall? or just a little laggy here and there? anyone have any advice for me? yes I know it's up to me, but I prefer to get input before I do it.