On iOS 7.1 Simulator, the cells are distorted in the CollectionView screen:

On iOS 8.0 and iOS 8.1 Simulator, navigating to CollectionView screen on Portrait and rotating it to Landscape will result in the cells not resizing correctly:

On iOS 8.0 and iOS 8.1 Simulator, rotating from Portrait to Landscape in TableView screen, followed by navigating to CollectionView screen, and rotating back to Portrait will result in the cells not resizing properly:

Please note that these issues are reproducible on both Xcode 6.0.1 (6A317) and Xcode 6.1 (6A1052d).
On iOS 7.1 Simulator, the cells are distorted in the CollectionView screen:
On iOS 8.0 and iOS 8.1 Simulator, navigating to CollectionView screen on Portrait and rotating it to Landscape will result in the cells not resizing correctly:
On iOS 8.0 and iOS 8.1 Simulator, rotating from Portrait to Landscape in TableView screen, followed by navigating to CollectionView screen, and rotating back to Portrait will result in the cells not resizing properly:
Please note that these issues are reproducible on both Xcode 6.0.1 (6A317) and Xcode 6.1 (6A1052d).