The possibility that we get to see a prime, full-on sith Vader lightsabering, forcing chocking, force jumping and force throwing people around like ragdolls is super nerdgasmic!
My question is whether or not it is currently considered canon that Vader can't use force lightning? I believe that idea arose from EU material that isn't canon anymore.
Vader focused on a different skillpath, he was focusing more on the Telekinetic Perks, like Force Choke etc.
Vader also put more points in the Melee-tree than Darth Sidious.
Sidious on the other hand specialized the Lightning-build.
Originally (spoiler), it was said that Vader would brutally maim, dismember and even decapitate the whole Rogue One-team (everyone killed by Vader) in one way or another, (early interview) but apparently they have done a more mellow version.
Hopefully we will at least see one or two dismemberments.