CT Vader or Luke?

They are what allows living being to connect with the Force, yes. But they aren't a measurement of power. More like potential. The more you have, the stronger your innate connection to the Force is.

 

Vader was more powerful throughout the Original Trilogy - he had a lifetime of experience with the Force, was trained with the blade by some of the greatest swordsmen of their time, and spent the majority of his life hunting and killing. He never goes full out on his son; with a flick of his finger, he could lift Luke in the air and start crushing his windpipe. Obviously he never did, because Vader never had the goal of killing Luke. Return of the Jedi is really interesting because that duel is based around two men holding back and shielding themselves: Luke is trying to protect himself from falling to the dark and Vader is struggling against his redemption. Luke loses his cool when Vader threatens Leia and he is caught off guard by this and by the time he's raised his lightsaber, he's too drained and unwilling to pull out the full stops against his own son. It is the good within Luke that makes him stronger than Vader; his lightsaber might have severed Vader's hand but he didn't win the fight until he pierced Vader's shell and revealed Anakin Skywalker underneath.

Whether or not Luke will become more powerful in the series, well, we will have to wait for the next movie to find out..

 

The sports analogy is pretty relevant. How often do we see super talented sports figures crash and burn because they're lazy, undisciplined, can't stay off drugs, etc.? Happens all the time. And good grief, we all know PT Anakin was a major head case. Luke was a little whiny and impatient early in the OT, but he grew out of it by ROTJ and was pretty steady by then.

 

I always thought Vader in his prime it would be no contest. Vader was old and clearly fading by ROTJ. In Empire Vader has several opportunities to kill Luke and doesn't. He's like a cat playing with a mouse.

 

In his prime Vader could have ruled the Galaxy. The Emperor strikes me as a pathetic figure towards the end. Luke was begging for help, Leia & Han were hold up down on the surface. Vader threw it all away when Luke chose not to join him at Bespin. Vader outlasted Obi-Wan and even Yoda this at a time when the Galaxy was plunged into chaos, Tyranny & depravity. Vader threw it all away and was driven to seek out Luke and lure him to the Darkness.

 

He's only forty six. He's not that far past his prime. Especially with what we saw Dooku was capable of and he was older. Same with Palpatine.

 

It's not the years it's the mileage. Vader has no legs and only one real arm.