最好用图像或编程自定义UINavigationBar？

I know that there are two distinct ways to customize a UINavigationBar: you can either set the background image to some custom png, or you could customize the bar's appearance in code, programmatically. If my aim is to support iOS 4,5,6 does it make sense to try to customize the bar's appearance through code?I know that there are two distinct ways to cust