I just got a new 4S and am trying to find a good hands-free solution. I have a 5 year old set of Shure E2cs that I love, and I think I may be able to kill two birds with one stone with the C5s. a couple questions that I have are: How is the mic quality on the C5? Any complaints from people on the other end of the line? How are the C5s with only one IEM in? I plan to use them while driving, and given their noise canceling ability I wouldn't feel safe with both in.