When my Infinity 6x9 died, I went to the dealer and got a replacement. ($70 at discount)
I would have gone aftermarket but every "stereo specialist" I talked to couldn't give me a satisfactory response. The first thing out of their mouths is "Well, first you get a new head unit". Nope, I like the unit I have. It plays taped & CDs and I can hit the buttons (usually) on the rough roads we have. I'd go nuts with those tiny buttons on some of those units. Can't justify the expense to loose functionality.