For me Che has a great voice (best in the category by far) but not much commercial appeal and seemingly little charisma. I think he needs to do more than just showcasing his vocal talent if he wants to be successful on the show. I don't think this show is just about having a good voice, it's about the ability to sell records.
Mason on the other hand has more potential imo. He's shown through a good variety of song choices that he's a versatile singer and performer, he has the full package. He's talented, good looking, interesting/entertaining and of course has a BIG personality. He could go far if he plays his cards right.