Sanogo is garbage - I see a lot more promise in Akpom's game albeit we're talking in relative terms here.
I can't remember what game it was last season where Akpom came on as a substitute and looked really lively. He seemed to have decent dribbling ability and was confident. Sanogo in comparison is clumsy, he carries the ball in a very laboured fashion and his decision making is painfully slow.
If we're going to give minutes to one of them, I would pick Akpom every time. It appears I am in a minority of people who like him though.