The speakerphone profile basically sets the parameters for the quality of audio produced and while 11.5MB maybe a bit bulky for such a minor change, Apple hasn't revealed any other changes this update has to offer.
If you wish you can also download the updates through the following official links and manually install it on your device using iTunes.
There is no news on whether this update will be released for other iOS devices. If you own a different handset you can check out the following updates for those devices.
- Download iOS 6.1.3 for iPhone, iPad and iPod Touch
- Download iOS 6.1.2 for iPhone, iPad and iPod Touch
Users who have installed iOS 6.1.2 and have jailbroken their device are advised to stay clear of the iOS 6.1.4 update if they want to retain their jailbreak. You can check out our jailbreaking guides if you want to jailbreak your iPhone, iPad or iPod Touch.