I've some experiences on build application with Asp.Net, but now MVC frameworks become more popular. I would like to try building new multilingual web application using with Asp.Net MVC or Castle MonoRail but I don't know which one is good for me. I don't like the web form view engine, but I like routing feature in Asp.Net MVC.
Speaking as an advocate of monorail, I've got to say you should probably go for ASP.NET MVC. To be honest, the simple fact that ASP.NET MVC is going to become the default architecture within three years should probably swing it. This equation was different a year ago, simply because the default architecture had serious productivity problems compared to MonoRail.
If you want to talk technical advantages and disadvantages:
Also, don't dismiss the standard view engine out of hand. You don't have to throw controls at it like you did with ASP.NET, you can code it in a pretty similar manner to Brail, only using C# instead of Boo.
There are things that are just plain ugly * the number of methods that take object for a parameter. Good luck finding the documentation on what exactly they expect. * Microsoft's fondness for abstract classes over interfaces. They have their reasons, but I still dislike it.
Also, in many ways, MonoRail remains the more complete platform. There's no abstraction for validation or paging in ASP.NET, for instance. Also, there's not really any help for binding to a model. The helpers have very little functionality compared to their Monorail equivalents.
Overall, though, I think ASP.NET MVC is a winner.