Thank you for the feedback.
Regarding our Xamarin offering and the Unified API - yes, we support that API since the end of January (removing the support for the monotouch API) as noted in this blog article
. It is strange that you experience issues regarding that matter. Please open a new support ticket and send a sample project, so that we can investigate the case accordingly.
Please also open a new ticket about the documentation issues you have encountered. Generally speaking, we are trying to cover the controls scenarios with both XAML and C# in the documentation. It is our demo app that currently uses code behind for the examples, and should we receive more feedback about the same, we will consider creating one more app which focuses on the XAML usage exclusively.