Deulofeu is a stop-and-go player, a bit similar to young Cristiano. Everytime he received the ball, he basically halted the enitre play and then used his acceleration to shake to shake his defender and deliver fine crosses and throughballs. That's what he's really good at and his final product is really decent,especially when compared to other Masia wingers like Adama.
However, him stopping the play everytime also killed any attacking flow. That's exactly the thing some Barca supporters (like Bernie) have against Neymar: while being an outstanding player, he tends to kill the attacking flow in order to deliver an individual action. Which tends to be frustrating every now and then. With Deulofeu being lesser player than Neymar, he'd probably struggle a lot in Barcelona right now.