Url Rewriting vs. Routing

I am making a making a new asp.net web forms site and would like to beautify my urls - I want to accept a url like this one "www.mysite.com/1-2,3" and turn it one like this "www.mysite.com/page.aspx?a=1&b=2&c=3". Which option is best for this task - IIS7 Url Rewriting or Routing in terms of performance and ease of maintenance. Btw I am planning to use medium trust shared hosting IIS7, maybe 6.

In the past I used PHP's mod_rewrite, which I was quite happy with, however now this whole site is being translated to ASP.NET, and I don't know which option to pick.

PS - I have already read this and this, however didn't find it clear enough for my problem.

I would make a strong argument for using routing. It keeps the request-resource resolution logic within your application, so it's very easy to add application-dependent logic when you need, and it eliminates the need to maintain synchronization between your application and a separate configuration resource.

Routing works great with traditional webforms.

URL rewriting is often (though not always) a compensation for a problem, rather than a solution - server software and frameworks still built around the older notion of web pages, which represent physical resources. However, web applications should react to requests as commands; but only relatively recent, modern web frameworks have begun to support that model natively. Routing is one of those developments.