Xamarin Form Custom Control

Hi,
I am new to Xamarin and want to make cross platform mobile apps. I got some experience in Windows Phone Apps development.
When I found something Xamarin.Form I was more excited, it seems that the coding for UI is XAML and almost similar to Windows Phone.
Now my question is:
1. If I use Xamarin.Form how far can I make custom UI for each platform or I can't?
2. As I am a Windows Phone developer its always easy for me to use XAML as the UI, so do you suggest me to use Xamarin.Form or the traditional UI creation using each platfrom tools?

Thanks