Hm, completely different experience here. I've been involved with three rather large Xamarin-Projects in the last year, and we were (team-wide) completely surprised at how much of the code can actually be shared, how our velocity compared to native development and the overall dev experience.
I think the code sharing thing really comes down to how you're using Xamarin – if you keep on writing apps the way you're used to from the original platforms, there's not much to gain. On the other hand adopting the patterns and ideas that influence the .NET sphere (DI/IoC, MVVM..), Code Sharing rates (or PCL vs. Native LoC) can be as high as 80/20.
Xamarin Studio certainly has its own shortcomings, but both Microsoft (Visual Studio for Mac) and Jetbrains (Project Rider) are actively improving or developing alternatives, so I think that pain is going to fade over time.
I think it's going to entirely depend on what type of app you have. Much like your parent comment, my experience with building an app was that very little code could actually be shared. In my case we had some fanciful design that would largely have to be custom code for each platform. Thinks like API calls, validation, business logic could be shared but that was negligible compared to the platform specific code.
Yes, and that's always going to be the case with cross platform development. Fancy UI/UX is going to be highly platform dependent, while projects that have more model/controller code are going to be easily shared.
I think the code sharing thing really comes down to how you're using Xamarin – if you keep on writing apps the way you're used to from the original platforms, there's not much to gain. On the other hand adopting the patterns and ideas that influence the .NET sphere (DI/IoC, MVVM..), Code Sharing rates (or PCL vs. Native LoC) can be as high as 80/20.
Xamarin Studio certainly has its own shortcomings, but both Microsoft (Visual Studio for Mac) and Jetbrains (Project Rider) are actively improving or developing alternatives, so I think that pain is going to fade over time.