KK you can do it, I have faith.
Plup is better than Duck, but you could definitely get comfortable in the matchup if you come out to MI for one of our tournaments. Once you get over the not knowing how to react to certain situations, it isn't so bad. I'm not quite there yet, but at the last smashfest I started to get a lot more comfortable.
and fair/bair are so damn good in the matchup it is absurd. Once you get the good fair spacing, you either get a hit --> grab, or hit-->DD grab (to avoid CC d-smash), or empty hop-->grab because they expect the fair. They are really damn good at keeping you off stage though, so hold the middle as long as possible, like any matchup. Really, all the games I lost I feel were because Duck got me off more and netted 40% or death from it.
EDIT: that is very obvious at the end. What I mean is, think of it like peach, if you go off the edge, she D-smashes you back off way too many times and you likely could have avoided the situation all together.