I'm currently evaluating Xamarin.Forms. As I can see the main issue is that through the standardisation of the UI you loose the plattform specific look and feel and it goes in the direction of PhoneGap apps or similar. On the other side you can write very fast code for all three plattforms. In my mind Xamarin.Forms seems to be suitable only for "simple" apps. Or am I wrong? If you try plattform specific adaptions it gets complicated and your time savings are gone.
So I want to find the advantages and disadvantages of Xamarin.Forms ... If you start once with Xamarin.Forms you stick with Xamarin.Forms. Currently, I don't see how you go back to use view controllers (iOS) and only sometimes use Xamarin.Forms for some screens. Furthermore, I read about performance issues. Is this strill true? A short test on an iPhone 4 brought an increased start up time (6 vs. 8 seconds). If you take into account that the Xamarin.Forms apps was very simple and the Xamarin.iOS app more complex this is a difference!
Is there a documentation out there which explains the Xamarin XAML dialect?
To come back to my main question: Are there any released apps out, which already uses Xamarin.Forms? Then I would get more insight about performance issues and what is possible.