He's not really new but I'll let it slide because I doubt a lot of people know about him.
He's definitely got flow and a unique voice. I really liked him on the song with Mike Posner. It fit really well. And the whole Mike Posner cd is amazing anyway.
I just can't get in to what he's rapping about. His biggest mixtape out right now is UKNOWBIGSEAN, I think he's coming out with a new one soon or already has I'm not up with him. But he raps about mostly getting rich. Sure that's a big part of hip hop culture is the drive to become wealthy and powerful, but he really talks about nothing else in his mixtape, it gets kinda dragged out.
Regardless, his voice is so unique, he'll go places.
Mike Posner is legit, drug dealer girl is an unreal tune, except for the end, that part is pretty gay. Big Sean is pretty dope too, nothing really special about him, check out "Who knows" ft. Big Sean on Mike Posner's mixtape, which you can also get for free on Itunes.