[ogdenyogly]

I have done a lot amount of development in MonoTouch / MonoDroid (full time for about 2.5 years now). I started using them back when they were beta, and I would wager we have one of the larger apps written in Xamarin (about 250kloc).

First of all, it's tricky. It took our team a long time to get the rhythm of simultaneous Android/iOS development. For a long time every single push broke something.

Some annoyances:

Visual studio project files don't merge. You need a special xml aware merge tool to do this. Even then, its a pain in the ass.

It can be very tricky to abstract the differences between Droid and iOS if you're interacting with the OS a lot.

Some things to know:

Just because you're in C# land, doesn't mean your API is. You're going to spend a lot of time implementing stuff in C# that feels wrong because your API is ObjC/Java.

Sometimes there isn't a good mapping between NS data types between the APIs.

You're going to spend a LOT of time in the iOS / Droid docs, so you'd better be comfortable with ObjC / Java.

Overall I'm happy with the experience.