Actually, that slippery feeling is what clean skin actually feels like. That not-slick sensation you’re used to feeling is soap scum – mineral deposits from tap water trapped in soap. Yum. 🙂
Well, I’m a fan of soft water so my bias is pretty clear. I’ve found that softened water does a better job of washing clothes and you can get away with using way less detergent than you would need otherwise (most of what detergent is doing is breaking down mineral deposits). When we’re out of soft water, I notice immediately.