The microphone in the iPhone 4S is pretty good – I have found it to capture excellent quality on all my consumer-ish recordings and videos. Of course, that is not to say it could not be improved.When the iRig MIC Cast was announced at CES this year, I was pretty excited. I have gotten a lot of use out of the original iRig MIC and this miniaturized version seemed poised to make my travel recordings an even more portable affair.