Personally I'm a Mason fan. Check out this video which shows the majority of his touches against Sunderland last season - the game in which he got injured.
For me it showcases his strengths and why I like him as a player, if he can maintain his best form. He always plays with his head up, always looking for a forward pass, can execute a good arsenal of short/medium/long passes, and makes good runs from deep into goal scoring positions.
Think his biggest weaknesses are finishing, defending and consistency. But personally I'd really like to see him stick around for one more season to see if he can stay consistent and injury free, and stake his claim as a dependable squad option.
Can anyone really watch that video and disagree that he has real strengths?