My husband is from the Palatinate, and I can understand the dialect reasonably well- probably better than a lot of native German speakers, who find it utterly incomprehansible. I've tried to listen to Schweitzerdeutsch and find it extremely hard to understand anything.

Having listened to a few recordings of Pennsylvania Dutch being spoken, I found that I could understand a resonable amount. My husband would understand more and he'd certainly be able to have a pretty reasonable conversation.