I honestly don't understand people giving Martin a hard time. Opposite of an attention seeker... literally never does anything with the media for pub. He doesn't player Twitter games, doesn't release "Top 10s", or do any of the other crap a lot of kids do.
ND got on him late and Michigan led, then they stopped recruiting him as they thought they'd be full up on WR and ND put themselves in very good position, and now Michigan wants him and that's probably where he wants to go. Remember that Denbrock was the primary guy getting ND back in the conversation and then he left... I think the new staff did as good of a job as they could pitching him but it's not surprising that someone would choose Michigan over ND right now given we have BK.
I'm a bit disappointed, because I really think ND would've landed him over Iowa, MSU, etc. It seemed patently obvious to me that he was not interested in staying in Iowa to play football and would probably pick the best fit for himself at a traditional Midwest power. Also, no one is sure where he's leaning because he doesn't talk to anyone. All information is sourced from "inside the Gug" or whatever the Michigan equivalent is. Until he tells a staff he is for sure coming to their school and it leaks out from them, no one knows exactly what he's going to do.