The (what is arguably a retcon) change from flashy, jumpy, acrobatic, superbeing bull**** Jedi lightsaber battles in the prequels to the broadsword slugging matches in this movie is a very good change, thematically speaking. Not only does it give each swing meaningful weight, it also opens up the door to allowing things to threaten main characters. A Jedi character who actually got a name in the prequels was functionally immune to anything that didn't also have a lightsaber. They couldn't be surprised, they couldn't be outfought, they could deflect or block absolutely anything and respond with immediately lethal or neutralizing force (heh) with minimal effort.
Contrast with Kylo Ren, Finn, and Rey. Finn has some martial training, but has handled a lightsaber in exactly one fight before (that he lost). He manages to hold his own against Kylo Ren for a few minutes, and though he eventually loses he actually inflicts a hit, while the tension is still at a high level. Rey has never handled a lightsaber before, but with the (inferred, but obvious) guidance of the force, she defeats Ren after a fairly lengthy and weighty battle. What does that mean? It means that normal characters can threaten force users now. It means that Jedi are not all majestic, flawless gymnasts capable of reaching low orbit with a light hop.
It shifts the focus of a Jedi or other force user's strength from literal physical strength and agility, and turns it toward the mystical aspects of the force. Kylo Ren is at his most powerful, most intimidating, and most interesting when he's using the power of the force, not when he's swinging a lightsaber.
He's also pretty obviously and deliberately set up as a wanna-be Darth Vader, both in and out of setting. It'll be interesting to see him get some genuine character development as he, Finn, and Rey all come into their own as the up and coming major players of the setting.