I actually prefer Xamarin Studio over Visual Studio (on Windows) in some respects. For example, the Xamarin.Forms XAML previewer is much better. Looking forward to a full designer.
P.S. I've got a four part blog post series this week on Xamarin.Forms. Starting with this today: https://unop.uk/cross-platform-native-mobile-app-development...
By the way, since it's based off MonoDevelop, you can just use it con Linux.
But most people writing the apps which then run on Linux, develop them on Macs (and the point of WSL is to give them a reason to consider Windows for this).
MS is going all Oracle-y on us, withdrawing from the consumer market as fast as they can, and heading for the green pastures of the corporate market, where fat happy companies are there to be milked. They are sick and tired of fighting for consumer money one penny at a time.
(XBox is probably not long for this world either.)
It still has a few bugs and hangs up on me once or twice a day. I think they should have those ironed out soon though.