Some changes were made in iOS 4.3 to further improve its interface. Some new icons have been introduced like facetime and camera interface has also been given a new look. Gingerbread has a darkened interface compared to the previous version. Changes have also been made in the keyboard.
Though Android 2.3 Gingerbread doesn't match the Honeycomb OS (which is for the tablets) but its the best Android version for smartphones that has come out till date. As far as the iOS 4.3 is concerned, not many changes have been made but it remains popular as ever.