ASP.NET is extremely heavyweight, late to implement asynchronous calls, hardly as agile as web platforms such as RoR.
I think you need to look further into what ASP.NET actually is! Web Forms is all that you describe (and its often worse). Check out the MVC framework, which replaces the web forms aspect with an MVC one.
I've been out of the loop for the last year and a half. If you reference me to a succinct overview of what I'm missing, I'll definitely read it.