It's a matter of opinion really, - I look at it in a few ways, but primarily I like the compare and contrast against the other players on the pitch - how do they react - the opposition, and how does the player compare to the best of the other players in the team. I remember the Defender injury season, Man City at home when they beat as 1-4 - prior to Curtis being taken off it was 1-1, and none of the City players dared to take him on in a dual of any kind. Our ball retention was better, - he gets taken off and we lose 1-4. That game is clear in my mind as if it was yesterday. Also compare him to the other midfielders in our squad, and I include Thiago in that, - Curtis can keep the ball better than he can, better dribbler, and more clinical in the penalty area. Klopp needs to use him right, and to be honest given how difficult it is in this league, if you were to compare him with other players in other European leagues with the same skill set, - I would always pick Curtis. I also think that most of the Liverpool community don't take to him because of the confidence he has in his abilities, I guess it does not conform to the Liverpool underdog bullshit mentality many of our supporters like to be associated with despite being England's premier European team. If Steven Gerrard thinks he is special then he is special.
I actually believe that if Curtis gets a run in the team, and proves to be as good as he really is, Real Madrid will come calling for him above any other player in our squad.