I've been working professionally with Xamarin for the past month, honestly I'm shocked how half-baked Xamarin Studio is, both in terms of stability and features. (Since we develop for iOS, we use Macs and VS is not an option).
Of course now that Microsoft has stepped in all the way, things may turn around, but my feeling is that the best window of opportunity for JetBrains would be to provide compelling Xamarin tooling on non-Windows platforms. That's the weak spot of their mammoth competitor as far as C# goes
https://forums.xamarin.com/discussion/62250/vote-for-project...
https://youtrack.jetbrains.com/oauth?state=%2Fissue%2FRIDER-...