Of course it's a luxury. What I find really enjoyable about it, I can reply to a text by tapping it and speaking. It is a lot more satisfying of an experience than it sounds like when described in words or even the videos used by Apple. It combines the best of the immediate talkback feature of Nextel with the benefits of asynchronous communication.
Where it really shined, I had my car in the dealer getting repaired. There was a lot of back and forth, and they used text messaging. So I could read the issue in about a second and dictate my answer and hit send. Each exchange happened in seconds compared to minutes that it would take via voice.