If anyone has used both, please let me know some overall impressions. I am considering building a game soon and am curious about the best platform moving forward.
Cocos2d-iphone is also really mature, compared to SpriteKit.
If you want something cross-platform, look into cocos2d-x, which uses C++, but you can use their JavaScript bindings.
This is all for 2D games. For 3D look into Unity.