Collin,

From what I understand, as long as you acquire a data stream, there isn't much of a problem with phase or noise.  Like most digital streams, it is either there, or it loses connectivity.  But because of the lower power of the IBOC passbands, it doesn't have the range.  I think this may also be true of FM Iboc, but I don't know.  I do know that FM IBOC will support mutliple channels, although I suspect a lot of broadcasters might put paid data streams on some of them.

It is similar with digital TV, to get a quality signal, you need a good high-gain antenna if you are any distance at all from the digital transmitter.  I think all this will be a big boon for the cable and satellite companies when analog goes dark in a couple years.

Steve, K8SP