Unlocked mobile phone handsets can be used on any GSM network globally. You can access all services that are offered by the local mobile phone operator.
If you are a frequent traveler, it is better for you to have an unlocked mobile phone handset, since you can use them on any GSM operator's network.
You have an advantage to customized setting of the mobile phone, completely and without any problem, while the locked mobile phones do not allow to change the preset settings.
You can update software and applications on the unlocked mobile phone handsets anytime without any problem. You can even download third-party applications, while this facility on the locked phone is not allowed.
Unlocked mobile phone handsets do not lack in features and quality. They are full of applications and features as much as the locked phone. In fact on the unlocked phone you can have more data communication freedom. It however can also pose some security risk to the device especially if you try to download any application from the websites, which are not trusted.
If you are using an unlocked mobile phone handset which was unlocked from the locked position, you might not be able to enjoy as much benefits as in case of the unlocked phone that you buy straight from the manufacturer.
Unlocked mobile phone handsets also tend to be more expensive than the locked phone, because in case of locked phone they are subsidized through the contract with the mobile phone network operator.