Should I update my iPhone 4 to the new iOS?

I just bought the new iPhone 4 and I'm wondering if its a good idea to update it. I heard it makes it slow and since I just got it I'm sort of useasy about updating it because I don't want to mess it up when I just got it. So is it a good idea?

With iphone 4 I would just stick with what you have for now because the hardware isn't made for iOS 7.