iOS 7.1 on the iPhone 4: as good as it's going to get
 

iOS 7 is unlikely to run better on the iPhone 4 than it does in iOS 7.1. That's not to say that the experience is great - even stepping up to an iPhone 4S would get you noticeable gains in performance and overall smoothness - but it's better than it was, and it's as good as it's going to get. If you're sticking with the iPhone 4 for another year, iOS 7.1 makes performance tolerable enough that using the phone isn't unbearable. Good news for iPhone 4 owners - and good on Apple for taking care of this demographic.

http://osnews.com/story/27607/iOS_7_...going_to_g et