iOS Auto Layout vs Springs & Struts

You should use Auto layout due to it's more updated way of using constraints

Auto Layout is the future and Springs & Struts is the past. If you continue to use Springs & Struts you will be at a disadvantage as the new standard - Auto Layout - becomes prevalent.

Also, Springs & Struts isn't effective for complex views. Auto Layout is considerably more powerful.

With iOS 7, it's early days, and although I'm not sure exactly what the implications are, the iOS 7 UI Transition Guide specifically mentions that using Auto Layout will ease the transition process:

If your app uses Auto Layout, your job is easier. In Xcode 5, Auto Layout can help an app accommodate new UI element metrics and respond appropriately to dynamic changes in text size. Auto Layout is particularly helpful if you’re transitioning an iOS 6 app or you need to support both iOS 6 and iOS 7.

If you didn’t use Auto Layout, now may be the perfect time to start, especially if you need to support more than one version of an app. If you use manual or programmatic layout techniques, you're responsible for ensuring that the layout adjusts appropriately when text size changes.

Personally, I've been using Auto Layout since Xcode 4.6.3. The initial learning curve is painful, but after that it really becomes a joy to use. I'd definitely never go back to Springs & Struts or manually calculating metrics using frames.

Yes you still can use Springs & Struts in iOS7, it works in my beta app although I had a bad time fixing my views but finally it works.

Please consider read the below:

If your application already uses Auto Layout, the development tool that automatically adjusts the layout to user’s viewing device resolution and orientation, your transition to the iOS7 will be fairly straightforward. If not, we recommend you evaluate whether you should start. The biggest reason why you should start is that now with iOS7 the user has the ability to change their text sizing, and your application in turn will be expected to respect this by updating the layout to support the desired text size. If you are using “Springs and Struts” or programmatic layout, then you will need to spend considerable time manipulating the views in order to get your layouts right. This can of course also affect the decision you make to support iOS6.

Reference here.