[gambler]

You're speaking as if doing AJAX and doing client-side MVC are one step apart. Moreover, you're speaking as if using server-side MVC forces the programmer to use no JavaScript at all. At best, this is naive. Either that, or you deliberately misrepresenting technologies to promote something.

The simplest way to use AJAX with a server-side MVC is by fetching blocks of pre-rendered HTML. This is commonly known as AHAH. It's dead-simple to do, powerful and trivial to use via progressive enhancement. That is what you should treat as the server-side alternative to client-side MVC.

[jiggy2011]

If your app has a lot of rich client functionality, it can be a lot easier to just use JSON data with client side MVC rather than having to constantly regenerate everything on the server, especially when several parts of the page need to be updated at once and a lot more performant.