I looked at Swift and Spritekit to create this tutorial series shortly after it was announced. This was before Xcode 6 was released and the language has evolved a bit.
Swift is nice enough, but it is going to have some glaring defects due to being developed in a vacuum. That said, it's a massive improvement over Objective-C. Frankly it's one of those languages you can learn incredibly easy and Playgrounds make it even easier. The biggest fight you will probably have is adapting ObjC documentation to Swift.
SpriteKit on the other hand is just frankly great. It's small, focused and effective. The only parts I found frustrating were ones that relied on underlying Cocoa libraries, like for geometry.
If you are going to develop exclusively for iOS ( and most recent ones to boot ), SpriteKit and Swift are a great pick.