I see Vader as a close in knife fighter against the Decimator while Fel will still be the Range 3 arc-dodging king.

So far, my experience playing Vader with proxy Raider stuff has been similar. He's not as frail as Soontir, so you can play him more aggressively and really get in there. Pick up an early target lock in the first exchange at range 3, then you can boost/barrel roll to range 1 pretty frequently and dice 3-4 damage with ATC and Predator.

When you're going in for a kill shot, it's fun to do the voice.