Monotouch or Titanium for rapid application development on IPhone?

As a .Net developer I always dreamed for the possibility to develop with my existing skills (c#) applications for the Iphone.

Both programs require a Mac and the Iphone Sdk installed.

Appcelerator Titanium was the first app I tried and it is based on exposing some Iphone native api to javascript so that they can be called using that language.

Monotouch starts at $399 for beeing able to deploy on the Iphone and not on the Iphone simulator while Titanium is free.

Monotouch (Monodevelop) has an Ide that is currently missing in Titanium (but you can use any editor like Textmate, Aptana...)

I think both program generate at the end a native precompiled app (also if I am not sure about the size of the final app on the Iphone as I think the .Net framework calls are prelilnked at compilation time in Monotouch).

I am also not sure about the full coverage of all the Iphone api and features.

Titanium has also the advantage to enable Android app development but as a c# developer I still find Monotouch experience more like the Visual Studio one.

Which one would you choose and what are your experiences on Monotouch and Titanium?