One of the minor things you have to deal with the Xperia line of phone  models is that they are usually one of the last Android phones to get an update. To cite an example, the Android 2.1 Froyo has just recently begun to be available over the Xperia line however it is not released simultaneously worldwide but by regional batches. This means that a person with an Xperia handset living in the UK would be able to enjoy Android 2.1 earlier than someone from Spain.