title: UIView Animation Blocks vs CAAnimation
body: <p>iOS animation experts! What are the pros and cons of each method? I know Apple recommends blocks instead of the old <code>UIView</code> animation methods (<code>UIView</code> <code>beginAnimations</code>, etc), but what about <code>CAAnimation</code>? When would you use one method vs the other? Is there a tradeoff in terms of performance?</p>