To my ears, when KTAR runs IBOC, they sound like crap. And so does KFYI, although some of their processing seems to make up for it. But since I even hear some of the IBOC hash on the main signal, I wish they'd do us a big favor and turn it off, writing it off as a bad investment, since it makes the already troubled AM band noisier, more delayed, and muddier. KTAR's seems to be off most mornings, and during daytime airings of most D-Backs games.
(Kind-of silly to bring your radio to the park and hear plays described 15 seconds later!)
Listening to Femino the other day, his voice was hard to recognize, the audio was _that_ muddy. If it needs that much work, turn it off and send it back.