To me what makes Acuna so great is his greatness. He doesn't have a real soft spot in his game and he's only 20. What will determine his long term success is going to be how he handles the league growing fearful of him. When you look at Trout, he didn't really start walking at a great rate until 3 seasons ago. He never was a poor walker mind you, but he didn't hit insane levels of 15+% until recently, because he learned the important lesson of sometimes pitchers won't pitch you. Acuna hopefully will learn the same and we'll see his K rate drop and his BB rate rise while he's still knocking the snot out of the ball.
Of course comparing anyone to Trout is not remotely fair, but I could also cite Votto, it wasn't until he was almost 30 that pitchers really started fearing him. That's what will determine Acuna's future success. How well he adjusts to adjusting, and if he does he's a true superstar.