I have been playing with my iPhone 5 this week, and today opened the Software Update app, to see 6.1.4 waiting for me.
Apple iOS 6.1.4 Update: http://support.apple.com/kb/DL1652
The install has been nice and smooth as with the 6.1.3 update. The update isn’t available on my iPhone 4 or new iPad yet.
Have just made a call using the speaker and the appears to be clearer. So well done Apple.