I have been playing with MonoTouch and haven't gotten all too far. I get the concepts of the XIB files and the C# is your typical syntax. My concerns are a lot with productivity. Keyboard shortcuts, refactoring, addons like ReSharper, etc. Those things become a crutch when you are hammering out work for clients and you need to do it fast.
If you are a ReSharper user or anything of the sort, I am sure you have come into a situation where you have a fresh installation of Visual Studio, yet no ReSharper, your client doesn't have licenses and doesn't allow you to use yours. That is the feeling of developing with MonoDevelop and MonoTouch. Of course you finally convince them to buy some licenses, and then you get to working. Well ESCOZ has come up with that convincing part. Although I have not tried it myself, I wanted to post it for anyone else who might be interested.
(I still think it is annoying that I have to buy a Mac, just to develop iPhone/iPad apps)