About Dual Wielder + Nick (New perspective)

Quote from HarmAssassin >>

The benefit of the Dual Wielding feat is that the second weapon doesn't need to be light, and you can draw/stow two weapons at once (again reinforcing the idea that dual wielding is the wielding of a weapon in each hand at the same time).

I'd say in 5.5 the main mechanical benefit is an extra BA attack that stacks with Nick, although it does also allow for thematic rapier/dagger pairings and the like

It's still a pretty massive downgrade from the 5.0 version in terms of which weapons you can use though. No more barbarians with twin battle axes