I have been working with Xamarin stuff for a couple years now, released about 7 apps with them and honestly cannot imagine another approach. I mainly work with smaller startups in specific line of business scenarios and it has become a necessity to not only have viable mobile offerings, but they have to have parity across platforms and support both phone and tablets. When I go into a sales meeting and pitch the idea that I can build for Android and iOS using the same language and sharing much of that code - I usually crush my competitors on price - which saves the customer money and makes more money for me (yipeee!)
The Forms work in Xamarin 3 seems lined up to make that pitch even easier and will likely help Xamarin grow into the enterprise even faster as ease of management in the code base is going to be a major driver in decisions for IT shops that now have to support a much more diverse platform set than they did in the days when a website was good enough.