The problem is that everyone in the new movies, to my mind, are constantly thinking 'Look Mom! I'm on Star Wars!'.
When the original actors were making the film, they were all unknowns who had everything to prove. They took it seriously, whereas there seems to be permanent smirks on half the faces in Ep1 & 2.
I will always take as an example, the final confrontation between Luke and Vader when compared to any Lightsabre battle in the modern movies. The Choreography is simple, scream and repeatedly use the Lightsabre as a club, and yet the pure passion of that entire scene, the lighting, the music, the fury on Luke's face has you gritting your teeth going 'YES! Kick his Arse Luke!'. The new ones have absolutely none of that emotional power.