I can't speak for all of them but I use Xamarin at work, and it absolutely does translate to native look and feel for the app. Although once you get to the GUI layer, it's not much more than a thin C# wrapper for the native OS framework and you have to write a lot of platform specific code. But everything else is cross-platform. And you're coding in C# and not Objective-C (or Java), which is a more predictable and less verbose experience, at least for me, and I've made half a dozen apps using Objective-C.